Dynamically access object property using variable

up vote
525
down vote

favorite

115

I'm trying to access a property of an object using a dynamic name. Is this possible?

const something = { bar: "Foobar!" };

const foo = 'bar';

something.foo; // The idea is to access something.bar, getting "Foobar!"

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

asked Nov 22 '10 at 11:23

RichW

3,18141729

3

See also property access: dot notation vs. brackets? and How do I add a property to an object using a variable as the name?
– Bergi
Nov 18 '14 at 6:11

add a comment |

up vote
525
down vote

favorite

115

I'm trying to access a property of an object using a dynamic name. Is this possible?

const something = { bar: "Foobar!" };

const foo = 'bar';

something.foo; // The idea is to access something.bar, getting "Foobar!"

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

asked Nov 22 '10 at 11:23

RichW

3,18141729

3

See also property access: dot notation vs. brackets? and How do I add a property to an object using a variable as the name?
– Bergi
Nov 18 '14 at 6:11

add a comment |

up vote
525
down vote

favorite

115

up vote
525
down vote

favorite

115

I'm trying to access a property of an object using a dynamic name. Is this possible?

const something = { bar: "Foobar!" };

const foo = 'bar';

something.foo; // The idea is to access something.bar, getting "Foobar!"

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

asked Nov 22 '10 at 11:23

RichW

3,18141729

I'm trying to access a property of an object using a dynamic name. Is this possible?

const something = { bar: "Foobar!" };

const foo = 'bar';

something.foo; // The idea is to access something.bar, getting "Foobar!"

javascript object properties

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

asked Nov 22 '10 at 11:23

RichW

3,18141729

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

asked Nov 22 '10 at 11:23

RichW

3,18141729

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

edited Mar 22 '17 at 16:12

Taryn♦

187k45284348

asked Nov 22 '10 at 11:23

RichW

3,18141729

asked Nov 22 '10 at 11:23

RichW

3,18141729

asked Nov 22 '10 at 11:23

RichW

3,18141729

3

See also property access: dot notation vs. brackets? and How do I add a property to an object using a variable as the name?
– Bergi
Nov 18 '14 at 6:11

add a comment |

3

See also property access: dot notation vs. brackets? and How do I add a property to an object using a variable as the name?
– Bergi
Nov 18 '14 at 6:11

See also property access: dot notation vs. brackets? and How do I add a property to an object using a variable as the name?
– Bergi
Nov 18 '14 at 6:11

add a comment |

11 Answers
11

active

oldest

votes

up vote
697
down vote

accepted

There are two ways to access properties of an object:

Dot notation: something.bar

Bracket notation: something['bar']

The value between the brackets can be any expression. Therefore, if the property name is stored in a variable, you have to use bracket notation:

var foo = 'bar';

something[foo];

// both x = something[foo] and something[foo] = x work as expected

edited Jan 2 at 18:05

Salman A

171k65328413

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

22

careful with this: javascript compilers will error here since they dont rename strings but they do rename object properties
– chacham15
Dec 6 '11 at 8:40

4

Some more info on why this is possible: JS objects are associative arrays, that's why. Further Reading: quirksmode.org/js/associative.html stackoverflow.com/questions/14031368/…
– dotnetguy
Jun 3 '14 at 9:00

@dotnetguy No they are not. Arrays are objects that inherit from the plain JS object prototype and therefore you can add properties a go-go like any plain object. The 'associative' behaviour is more object-like than array like. You can't iterate the 'associative' version by simple index so it is not displaying array-like behaviour. You can define your 'associative' array as {} or and treat it the same in either case as far as random property access is concerned.
– Vanquished Wombat
Jan 3 '17 at 16:01

2

@VanquishedWombat Not sure what your objection pertains to? I did not say that JS Objects are arrays?
– dotnetguy
Jan 6 '17 at 0:30

as a reference to the correct answer , Reference
– youhana
Jun 8 '17 at 21:23

|
show 2 more comments

up vote
43
down vote

This is my solution:

function resolve(path, obj) {

    return path.split('.').reduce(function(prev, curr) {

        return prev ? prev[curr] : null

    }, obj || self)

}

Usage examples:

resolve("document.body.style.width")

// or

resolve("style.width", document.body)

// or even use array indexes

// (someObject has been defined in the question)

resolve("part.0.size", someObject) 

// returns null when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

answered Jul 26 '17 at 8:57

abahet

2,85111817

4

This is similar to lodash get
– Moby Disk
Dec 15 '17 at 14:06

add a comment |

up vote
26
down vote

In javascript we can access with:

dot notation - foo.bar

square brackets - foo[someVar] or foo["string"]

But only second case allows to access properties dynamically:

var foo = { pName1 : 1, pName2 : [1, {foo : bar }, 3] , ...}



var name = "pName"

var num  = 1;



foo[name + num]; // 1



// -- 



var a = 2;

var b = 1;

var c = "foo";



foo[name + a][b][c]; // bar

answered Jul 1 '14 at 15:40

Sonique

2,32442539

1

I'm staring at 2,000 lines of if statements because the previous dev didn't use square brackets, and statically accessed object properties by dot notation. It's for an approval process app that has 7 different approvers and the steps are all the same. /rip
– Chad
Jun 7 at 14:28

add a comment |

up vote
15
down vote

Following is an ES6 example of how you can access the property of an object using a property name that has been dynamically generated by concatenating two strings.

var suffix = " name";



var person = {

    ["first" + suffix]: "Nicholas",

    ["last" + suffix]: "Zakas"

};



console.log(person["first name"]);      // "Nicholas"

console.log(person["last name"]);       // "Zakas"

This is called computed property names

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

answered Aug 2 '16 at 19:46

zloctb

4,54233946

add a comment |

up vote
12
down vote

You can achieve this in quite a few different ways.

let foo = {

    bar: 'Hello World'

};



foo.bar;

foo['bar'];

The bracket notation is specially powerful as it let's you access a property based on a variable:

let foo = {

    bar: 'Hello World'

};



let prop = 'bar';



foo[prop];

This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



for (let prop in foo.getOwnPropertyNames()) {

    console.log(foo[prop]);

}

Both dot and bracket notation also work as expected for nested objects:

let foo = {

    bar: {

        baz: 'Hello World'

    }

};



foo.bar.baz;

foo['bar']['baz'];

foo.bar['baz'];

foo['bar'].baz;

Object destructuring

We could also consider object destructuring as a means to access a property in an object, but as follows:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



let prop = 'last';

let { bar, baz, [prop]: customName } = foo;



// bar = 'Hello World'

// baz = 'How are you doing?'

// customName = 'Quite alright'

edited Dec 13 '17 at 8:06

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

add a comment |

up vote
4
down vote

UPDATED

I have take comments below into consideration and agreed. Eval is to be avoided.

Accessing root properties in object is easily achieved with obj[variable], but getting nested complicates thing. Not to write already written code I suggest to use lodash.get.

Example

// Accessing root property

var rootProp = 'rootPropert';

_.get(object, rootProp, defaultValue);



// Accessing nested property

var listOfNestedProperties = [var1, var2];

_.get(object, listOfNestedProperties);

Lodash get can be used on different ways, here is link to the documentation lodash.get

edited Jun 19 at 9:29

answered Jun 22 '15 at 8:10

Mr Br

1,489916

4

It's best to avoid using eval whenever possible. stackoverflow.com/questions/86513/…
– Luke
Jun 23 '15 at 18:07

7

Using eval for something as trivial as accessing properties is plain overkill and hardly advisable under any circumstance. What's "trouble"? obj['nested']['test'] works very well and doesn't require you to embed code in strings.
– Paul Stenne
Oct 23 '15 at 10:14

3

eval is three times slower or more, I wouldn't recommend this to newbies because it might teach them bad habits. I use obj['nested']['value'] - remember kids, eval is evil!
– jaggedsoft
Nov 26 '15 at 1:25

1

@Luke He's now the only want to bring Lodash _.get to the table. I think this answer deserves now upvotes instead of downvotes. It may be overkill, but it's good to know it exists.
– Emile Bergeron
Dec 20 '16 at 21:42

1

Thank you for introducing lodash for this. I came here by google looking for a method to set a value deep in an object, and used their _.set method (which is identical to above but with the extra arguement for the value to set).
– TPHughes
Jul 3 at 9:03

|
show 3 more comments

up vote
2
down vote

Whenever you need to access property dynamically you have to use square bracket for accessing property not "." operator

Syntax: object[propery}

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

edited Jul 31 at 8:25

Manasi

434314

answered Jul 31 at 8:24

Rupesh Agrawal

632419

add a comment |

up vote
2
down vote

You can do it like this using Lodash get

_.get(object, 'a[0].b.c');

edited Sep 6 at 15:57

JJJ

29k147591

answered Sep 6 at 6:36

shalonteoh

2151311

add a comment |

up vote
1
down vote

It gets interesting when you have to pass parameters to this function as well.

Code jsfiddle

var obj = {method:function(p1,p2,p3){console.log("method:",arguments)}}



var str = "method('p1', 'p2', 'p3');"



var match = str.match(/^s*(S+)((.*));s*$/);



var func = match[1]

var parameters = match[2].split(',');

for(var i = 0; i < parameters.length; ++i) {

  // clean up param begninning

    parameters[i] = parameters[i].replace(/^s*['"]?/,'');

  // clean up param end

  parameters[i] = parameters[i].replace(/['"]?s*$/,'');

}



obj[func](parameters); // sends parameters as array

obj[func].apply(this, parameters); // sends parameters as individual values

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

add a comment |

up vote
-3
down vote

You should use JSON.parse, take a look at https://www.w3schools.com/js/js_json_parse.asp

const obj = JSON.parse('{ "name":"John", "age":30, "city":"New York"}')

console.log(obj.name)

console.log(obj.age)

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

add a comment |

up vote
-4
down vote

const something = { bar: "Foobar!" };

const foo = 'bar';



something[`${foo}`];

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

answered Jul 2 '17 at 19:04

Sergey

984

6

Why on earth would you do that? Your foo is already a string, so `${foo}` is exactly the same as foo. (Also, your code seems to have some extra backslashes that don't belong there. But it would still be pointless even if you fixed that syntax error.)
– Ilmari Karonen
Sep 19 '17 at 18:49

add a comment |

protected by Samuel Liew♦ Oct 5 '15 at 9:00

Thank you for your interest in this question.
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11 Answers
11

active

oldest

votes

11 Answers
11

active

oldest

votes

up vote
697
down vote

accepted

There are two ways to access properties of an object:

Dot notation: something.bar

Bracket notation: something['bar']

The value between the brackets can be any expression. Therefore, if the property name is stored in a variable, you have to use bracket notation:

var foo = 'bar';

something[foo];

// both x = something[foo] and something[foo] = x work as expected

edited Jan 2 at 18:05

Salman A

171k65328413

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

22

careful with this: javascript compilers will error here since they dont rename strings but they do rename object properties
– chacham15
Dec 6 '11 at 8:40

4

Some more info on why this is possible: JS objects are associative arrays, that's why. Further Reading: quirksmode.org/js/associative.html stackoverflow.com/questions/14031368/…
– dotnetguy
Jun 3 '14 at 9:00

@dotnetguy No they are not. Arrays are objects that inherit from the plain JS object prototype and therefore you can add properties a go-go like any plain object. The 'associative' behaviour is more object-like than array like. You can't iterate the 'associative' version by simple index so it is not displaying array-like behaviour. You can define your 'associative' array as {} or and treat it the same in either case as far as random property access is concerned.
– Vanquished Wombat
Jan 3 '17 at 16:01

2

@VanquishedWombat Not sure what your objection pertains to? I did not say that JS Objects are arrays?
– dotnetguy
Jan 6 '17 at 0:30

as a reference to the correct answer , Reference
– youhana
Jun 8 '17 at 21:23

|
show 2 more comments

up vote
697
down vote

accepted

There are two ways to access properties of an object:

Dot notation: something.bar

Bracket notation: something['bar']

The value between the brackets can be any expression. Therefore, if the property name is stored in a variable, you have to use bracket notation:

var foo = 'bar';

something[foo];

// both x = something[foo] and something[foo] = x work as expected

edited Jan 2 at 18:05

Salman A

171k65328413

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

22

careful with this: javascript compilers will error here since they dont rename strings but they do rename object properties
– chacham15
Dec 6 '11 at 8:40

4

Some more info on why this is possible: JS objects are associative arrays, that's why. Further Reading: quirksmode.org/js/associative.html stackoverflow.com/questions/14031368/…
– dotnetguy
Jun 3 '14 at 9:00

@dotnetguy No they are not. Arrays are objects that inherit from the plain JS object prototype and therefore you can add properties a go-go like any plain object. The 'associative' behaviour is more object-like than array like. You can't iterate the 'associative' version by simple index so it is not displaying array-like behaviour. You can define your 'associative' array as {} or and treat it the same in either case as far as random property access is concerned.
– Vanquished Wombat
Jan 3 '17 at 16:01

2

@VanquishedWombat Not sure what your objection pertains to? I did not say that JS Objects are arrays?
– dotnetguy
Jan 6 '17 at 0:30

as a reference to the correct answer , Reference
– youhana
Jun 8 '17 at 21:23

|
show 2 more comments

up vote
697
down vote

accepted

There are two ways to access properties of an object:

Dot notation: something.bar

Bracket notation: something['bar']

The value between the brackets can be any expression. Therefore, if the property name is stored in a variable, you have to use bracket notation:

var foo = 'bar';

something[foo];

// both x = something[foo] and something[foo] = x work as expected

edited Jan 2 at 18:05

Salman A

171k65328413

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

There are two ways to access properties of an object:

Dot notation: something.bar

Bracket notation: something['bar']

The value between the brackets can be any expression. Therefore, if the property name is stored in a variable, you have to use bracket notation:

var foo = 'bar';

something[foo];

// both x = something[foo] and something[foo] = x work as expected

edited Jan 2 at 18:05

Salman A

171k65328413

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

edited Jan 2 at 18:05

Salman A

171k65328413

edited Jan 2 at 18:05

Salman A

171k65328413

edited Jan 2 at 18:05

Salman A

171k65328413

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

answered Nov 22 '10 at 11:25

Jan Hančič

40.4k138189

22

careful with this: javascript compilers will error here since they dont rename strings but they do rename object properties
– chacham15
Dec 6 '11 at 8:40

4

Some more info on why this is possible: JS objects are associative arrays, that's why. Further Reading: quirksmode.org/js/associative.html stackoverflow.com/questions/14031368/…
– dotnetguy
Jun 3 '14 at 9:00

@dotnetguy No they are not. Arrays are objects that inherit from the plain JS object prototype and therefore you can add properties a go-go like any plain object. The 'associative' behaviour is more object-like than array like. You can't iterate the 'associative' version by simple index so it is not displaying array-like behaviour. You can define your 'associative' array as {} or and treat it the same in either case as far as random property access is concerned.
– Vanquished Wombat
Jan 3 '17 at 16:01

2

@VanquishedWombat Not sure what your objection pertains to? I did not say that JS Objects are arrays?
– dotnetguy
Jan 6 '17 at 0:30

as a reference to the correct answer , Reference
– youhana
Jun 8 '17 at 21:23

|
show 2 more comments

22

careful with this: javascript compilers will error here since they dont rename strings but they do rename object properties
– chacham15
Dec 6 '11 at 8:40

4

Some more info on why this is possible: JS objects are associative arrays, that's why. Further Reading: quirksmode.org/js/associative.html stackoverflow.com/questions/14031368/…
– dotnetguy
Jun 3 '14 at 9:00

@dotnetguy No they are not. Arrays are objects that inherit from the plain JS object prototype and therefore you can add properties a go-go like any plain object. The 'associative' behaviour is more object-like than array like. You can't iterate the 'associative' version by simple index so it is not displaying array-like behaviour. You can define your 'associative' array as {} or and treat it the same in either case as far as random property access is concerned.
– Vanquished Wombat
Jan 3 '17 at 16:01

2

@VanquishedWombat Not sure what your objection pertains to? I did not say that JS Objects are arrays?
– dotnetguy
Jan 6 '17 at 0:30

as a reference to the correct answer , Reference
– youhana
Jun 8 '17 at 21:23

careful with this: javascript compilers will error here since they dont rename strings but they do rename object properties
– chacham15
Dec 6 '11 at 8:40

Some more info on why this is possible: JS objects are associative arrays, that's why. Further Reading: quirksmode.org/js/associative.html stackoverflow.com/questions/14031368/…
– dotnetguy
Jun 3 '14 at 9:00

@dotnetguy No they are not. Arrays are objects that inherit from the plain JS object prototype and therefore you can add properties a go-go like any plain object. The 'associative' behaviour is more object-like than array like. You can't iterate the 'associative' version by simple index so it is not displaying array-like behaviour. You can define your 'associative' array as {} or and treat it the same in either case as far as random property access is concerned.
– Vanquished Wombat
Jan 3 '17 at 16:01

@VanquishedWombat Not sure what your objection pertains to? I did not say that JS Objects are arrays?
– dotnetguy
Jan 6 '17 at 0:30

as a reference to the correct answer , Reference
– youhana
Jun 8 '17 at 21:23

|
show 2 more comments

up vote
43
down vote

This is my solution:

function resolve(path, obj) {

    return path.split('.').reduce(function(prev, curr) {

        return prev ? prev[curr] : null

    }, obj || self)

}

Usage examples:

resolve("document.body.style.width")

// or

resolve("style.width", document.body)

// or even use array indexes

// (someObject has been defined in the question)

resolve("part.0.size", someObject) 

// returns null when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

answered Jul 26 '17 at 8:57

abahet

2,85111817

4

This is similar to lodash get
– Moby Disk
Dec 15 '17 at 14:06

add a comment |

up vote
43
down vote

This is my solution:

function resolve(path, obj) {

    return path.split('.').reduce(function(prev, curr) {

        return prev ? prev[curr] : null

    }, obj || self)

}

Usage examples:

resolve("document.body.style.width")

// or

resolve("style.width", document.body)

// or even use array indexes

// (someObject has been defined in the question)

resolve("part.0.size", someObject) 

// returns null when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

answered Jul 26 '17 at 8:57

abahet

2,85111817

4

This is similar to lodash get
– Moby Disk
Dec 15 '17 at 14:06

add a comment |

up vote
43
down vote

This is my solution:

function resolve(path, obj) {

    return path.split('.').reduce(function(prev, curr) {

        return prev ? prev[curr] : null

    }, obj || self)

}

Usage examples:

resolve("document.body.style.width")

// or

resolve("style.width", document.body)

// or even use array indexes

// (someObject has been defined in the question)

resolve("part.0.size", someObject) 

// returns null when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

answered Jul 26 '17 at 8:57

abahet

2,85111817

This is my solution:

function resolve(path, obj) {

    return path.split('.').reduce(function(prev, curr) {

        return prev ? prev[curr] : null

    }, obj || self)

}

Usage examples:

resolve("document.body.style.width")

// or

resolve("style.width", document.body)

// or even use array indexes

// (someObject has been defined in the question)

resolve("part.0.size", someObject) 

// returns null when intermediate properties are not defined:

resolve('properties.that.do.not.exist', {hello:'world'})

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

answered Jul 26 '17 at 8:57

abahet

2,85111817

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

edited Sep 23 '17 at 14:45

GeekyDeaks

500511

answered Jul 26 '17 at 8:57

abahet

2,85111817

answered Jul 26 '17 at 8:57

abahet

2,85111817

answered Jul 26 '17 at 8:57

abahet

2,85111817

4

This is similar to lodash get
– Moby Disk
Dec 15 '17 at 14:06

add a comment |

4

This is similar to lodash get
– Moby Disk
Dec 15 '17 at 14:06

This is similar to lodash get
– Moby Disk
Dec 15 '17 at 14:06

add a comment |

up vote
26
down vote

In javascript we can access with:

dot notation - foo.bar

square brackets - foo[someVar] or foo["string"]

But only second case allows to access properties dynamically:

var foo = { pName1 : 1, pName2 : [1, {foo : bar }, 3] , ...}



var name = "pName"

var num  = 1;



foo[name + num]; // 1



// -- 



var a = 2;

var b = 1;

var c = "foo";



foo[name + a][b][c]; // bar

answered Jul 1 '14 at 15:40

Sonique

2,32442539

1

I'm staring at 2,000 lines of if statements because the previous dev didn't use square brackets, and statically accessed object properties by dot notation. It's for an approval process app that has 7 different approvers and the steps are all the same. /rip
– Chad
Jun 7 at 14:28

add a comment |

up vote
26
down vote

In javascript we can access with:

dot notation - foo.bar

square brackets - foo[someVar] or foo["string"]

But only second case allows to access properties dynamically:

var foo = { pName1 : 1, pName2 : [1, {foo : bar }, 3] , ...}



var name = "pName"

var num  = 1;



foo[name + num]; // 1



// -- 



var a = 2;

var b = 1;

var c = "foo";



foo[name + a][b][c]; // bar

answered Jul 1 '14 at 15:40

Sonique

2,32442539

1

I'm staring at 2,000 lines of if statements because the previous dev didn't use square brackets, and statically accessed object properties by dot notation. It's for an approval process app that has 7 different approvers and the steps are all the same. /rip
– Chad
Jun 7 at 14:28

add a comment |

up vote
26
down vote

In javascript we can access with:

dot notation - foo.bar

square brackets - foo[someVar] or foo["string"]

But only second case allows to access properties dynamically:

var foo = { pName1 : 1, pName2 : [1, {foo : bar }, 3] , ...}



var name = "pName"

var num  = 1;



foo[name + num]; // 1



// -- 



var a = 2;

var b = 1;

var c = "foo";



foo[name + a][b][c]; // bar

answered Jul 1 '14 at 15:40

Sonique

2,32442539

In javascript we can access with:

dot notation - foo.bar

square brackets - foo[someVar] or foo["string"]

But only second case allows to access properties dynamically:

var foo = { pName1 : 1, pName2 : [1, {foo : bar }, 3] , ...}



var name = "pName"

var num  = 1;



foo[name + num]; // 1



// -- 



var a = 2;

var b = 1;

var c = "foo";



foo[name + a][b][c]; // bar

answered Jul 1 '14 at 15:40

Sonique

2,32442539

answered Jul 1 '14 at 15:40

Sonique

2,32442539

answered Jul 1 '14 at 15:40

Sonique

2,32442539

answered Jul 1 '14 at 15:40

Sonique

2,32442539

1

I'm staring at 2,000 lines of if statements because the previous dev didn't use square brackets, and statically accessed object properties by dot notation. It's for an approval process app that has 7 different approvers and the steps are all the same. /rip
– Chad
Jun 7 at 14:28

add a comment |

1

I'm staring at 2,000 lines of if statements because the previous dev didn't use square brackets, and statically accessed object properties by dot notation. It's for an approval process app that has 7 different approvers and the steps are all the same. /rip
– Chad
Jun 7 at 14:28

I'm staring at 2,000 lines of if statements because the previous dev didn't use square brackets, and statically accessed object properties by dot notation. It's for an approval process app that has 7 different approvers and the steps are all the same. /rip
– Chad
Jun 7 at 14:28

add a comment |

up vote
15
down vote

Following is an ES6 example of how you can access the property of an object using a property name that has been dynamically generated by concatenating two strings.

var suffix = " name";



var person = {

    ["first" + suffix]: "Nicholas",

    ["last" + suffix]: "Zakas"

};



console.log(person["first name"]);      // "Nicholas"

console.log(person["last name"]);       // "Zakas"

This is called computed property names

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

answered Aug 2 '16 at 19:46

zloctb

4,54233946

add a comment |

up vote
15
down vote

Following is an ES6 example of how you can access the property of an object using a property name that has been dynamically generated by concatenating two strings.

var suffix = " name";



var person = {

    ["first" + suffix]: "Nicholas",

    ["last" + suffix]: "Zakas"

};



console.log(person["first name"]);      // "Nicholas"

console.log(person["last name"]);       // "Zakas"

This is called computed property names

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

answered Aug 2 '16 at 19:46

zloctb

4,54233946

add a comment |

up vote
15
down vote

Following is an ES6 example of how you can access the property of an object using a property name that has been dynamically generated by concatenating two strings.

var suffix = " name";



var person = {

    ["first" + suffix]: "Nicholas",

    ["last" + suffix]: "Zakas"

};



console.log(person["first name"]);      // "Nicholas"

console.log(person["last name"]);       // "Zakas"

This is called computed property names

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

answered Aug 2 '16 at 19:46

zloctb

4,54233946

Following is an ES6 example of how you can access the property of an object using a property name that has been dynamically generated by concatenating two strings.

var suffix = " name";



var person = {

    ["first" + suffix]: "Nicholas",

    ["last" + suffix]: "Zakas"

};



console.log(person["first name"]);      // "Nicholas"

console.log(person["last name"]);       // "Zakas"

This is called computed property names

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

answered Aug 2 '16 at 19:46

zloctb

4,54233946

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

edited Jul 10 '17 at 6:11

try-catch-finally

4,53242249

answered Aug 2 '16 at 19:46

zloctb

4,54233946

answered Aug 2 '16 at 19:46

zloctb

4,54233946

answered Aug 2 '16 at 19:46

zloctb

4,54233946

add a comment |

up vote
12
down vote

You can achieve this in quite a few different ways.

let foo = {

    bar: 'Hello World'

};



foo.bar;

foo['bar'];

The bracket notation is specially powerful as it let's you access a property based on a variable:

let foo = {

    bar: 'Hello World'

};



let prop = 'bar';



foo[prop];

This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



for (let prop in foo.getOwnPropertyNames()) {

    console.log(foo[prop]);

}

Both dot and bracket notation also work as expected for nested objects:

let foo = {

    bar: {

        baz: 'Hello World'

    }

};



foo.bar.baz;

foo['bar']['baz'];

foo.bar['baz'];

foo['bar'].baz;

Object destructuring

We could also consider object destructuring as a means to access a property in an object, but as follows:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



let prop = 'last';

let { bar, baz, [prop]: customName } = foo;



// bar = 'Hello World'

// baz = 'How are you doing?'

// customName = 'Quite alright'

edited Dec 13 '17 at 8:06

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

add a comment |

up vote
12
down vote

You can achieve this in quite a few different ways.

let foo = {

    bar: 'Hello World'

};



foo.bar;

foo['bar'];

The bracket notation is specially powerful as it let's you access a property based on a variable:

let foo = {

    bar: 'Hello World'

};



let prop = 'bar';



foo[prop];

This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



for (let prop in foo.getOwnPropertyNames()) {

    console.log(foo[prop]);

}

Both dot and bracket notation also work as expected for nested objects:

let foo = {

    bar: {

        baz: 'Hello World'

    }

};



foo.bar.baz;

foo['bar']['baz'];

foo.bar['baz'];

foo['bar'].baz;

Object destructuring

We could also consider object destructuring as a means to access a property in an object, but as follows:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



let prop = 'last';

let { bar, baz, [prop]: customName } = foo;



// bar = 'Hello World'

// baz = 'How are you doing?'

// customName = 'Quite alright'

edited Dec 13 '17 at 8:06

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

add a comment |

up vote
12
down vote

You can achieve this in quite a few different ways.

let foo = {

    bar: 'Hello World'

};



foo.bar;

foo['bar'];

The bracket notation is specially powerful as it let's you access a property based on a variable:

let foo = {

    bar: 'Hello World'

};



let prop = 'bar';



foo[prop];

This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



for (let prop in foo.getOwnPropertyNames()) {

    console.log(foo[prop]);

}

Both dot and bracket notation also work as expected for nested objects:

let foo = {

    bar: {

        baz: 'Hello World'

    }

};



foo.bar.baz;

foo['bar']['baz'];

foo.bar['baz'];

foo['bar'].baz;

Object destructuring

We could also consider object destructuring as a means to access a property in an object, but as follows:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



let prop = 'last';

let { bar, baz, [prop]: customName } = foo;



// bar = 'Hello World'

// baz = 'How are you doing?'

// customName = 'Quite alright'

edited Dec 13 '17 at 8:06

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

You can achieve this in quite a few different ways.

let foo = {

    bar: 'Hello World'

};



foo.bar;

foo['bar'];

The bracket notation is specially powerful as it let's you access a property based on a variable:

let foo = {

    bar: 'Hello World'

};



let prop = 'bar';



foo[prop];

This can be extended to looping over every property of an object. This can be seem redundant due to newer JavaScript constructs such as for ... of ..., but helps illustrate a use case:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



for (let prop in foo.getOwnPropertyNames()) {

    console.log(foo[prop]);

}

Both dot and bracket notation also work as expected for nested objects:

let foo = {

    bar: {

        baz: 'Hello World'

    }

};



foo.bar.baz;

foo['bar']['baz'];

foo.bar['baz'];

foo['bar'].baz;

Object destructuring

We could also consider object destructuring as a means to access a property in an object, but as follows:

let foo = {

    bar: 'Hello World',

    baz: 'How are you doing?',

    last: 'Quite alright'

};



let prop = 'last';

let { bar, baz, [prop]: customName } = foo;



// bar = 'Hello World'

// baz = 'How are you doing?'

// customName = 'Quite alright'

edited Dec 13 '17 at 8:06

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

edited Dec 13 '17 at 8:06

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

answered Mar 8 '17 at 11:30

Gorka Hernandez

2,287823

add a comment |

up vote
4
down vote

UPDATED

I have take comments below into consideration and agreed. Eval is to be avoided.

Accessing root properties in object is easily achieved with obj[variable], but getting nested complicates thing. Not to write already written code I suggest to use lodash.get.

Example

// Accessing root property

var rootProp = 'rootPropert';

_.get(object, rootProp, defaultValue);



// Accessing nested property

var listOfNestedProperties = [var1, var2];

_.get(object, listOfNestedProperties);

Lodash get can be used on different ways, here is link to the documentation lodash.get

edited Jun 19 at 9:29

answered Jun 22 '15 at 8:10

Mr Br

1,489916

4

It's best to avoid using eval whenever possible. stackoverflow.com/questions/86513/…
– Luke
Jun 23 '15 at 18:07

7

Using eval for something as trivial as accessing properties is plain overkill and hardly advisable under any circumstance. What's "trouble"? obj['nested']['test'] works very well and doesn't require you to embed code in strings.
– Paul Stenne
Oct 23 '15 at 10:14

3

eval is three times slower or more, I wouldn't recommend this to newbies because it might teach them bad habits. I use obj['nested']['value'] - remember kids, eval is evil!
– jaggedsoft
Nov 26 '15 at 1:25

1

@Luke He's now the only want to bring Lodash _.get to the table. I think this answer deserves now upvotes instead of downvotes. It may be overkill, but it's good to know it exists.
– Emile Bergeron
Dec 20 '16 at 21:42

1

Thank you for introducing lodash for this. I came here by google looking for a method to set a value deep in an object, and used their _.set method (which is identical to above but with the extra arguement for the value to set).
– TPHughes
Jul 3 at 9:03

|
show 3 more comments

up vote
4
down vote

UPDATED

I have take comments below into consideration and agreed. Eval is to be avoided.

Accessing root properties in object is easily achieved with obj[variable], but getting nested complicates thing. Not to write already written code I suggest to use lodash.get.

Example

// Accessing root property

var rootProp = 'rootPropert';

_.get(object, rootProp, defaultValue);



// Accessing nested property

var listOfNestedProperties = [var1, var2];

_.get(object, listOfNestedProperties);

Lodash get can be used on different ways, here is link to the documentation lodash.get

edited Jun 19 at 9:29

answered Jun 22 '15 at 8:10

Mr Br

1,489916

4

It's best to avoid using eval whenever possible. stackoverflow.com/questions/86513/…
– Luke
Jun 23 '15 at 18:07

7

Using eval for something as trivial as accessing properties is plain overkill and hardly advisable under any circumstance. What's "trouble"? obj['nested']['test'] works very well and doesn't require you to embed code in strings.
– Paul Stenne
Oct 23 '15 at 10:14

3

eval is three times slower or more, I wouldn't recommend this to newbies because it might teach them bad habits. I use obj['nested']['value'] - remember kids, eval is evil!
– jaggedsoft
Nov 26 '15 at 1:25

1

@Luke He's now the only want to bring Lodash _.get to the table. I think this answer deserves now upvotes instead of downvotes. It may be overkill, but it's good to know it exists.
– Emile Bergeron
Dec 20 '16 at 21:42

1

Thank you for introducing lodash for this. I came here by google looking for a method to set a value deep in an object, and used their _.set method (which is identical to above but with the extra arguement for the value to set).
– TPHughes
Jul 3 at 9:03

|
show 3 more comments

up vote
4
down vote

UPDATED

I have take comments below into consideration and agreed. Eval is to be avoided.

Accessing root properties in object is easily achieved with obj[variable], but getting nested complicates thing. Not to write already written code I suggest to use lodash.get.

Example

// Accessing root property

var rootProp = 'rootPropert';

_.get(object, rootProp, defaultValue);



// Accessing nested property

var listOfNestedProperties = [var1, var2];

_.get(object, listOfNestedProperties);

Lodash get can be used on different ways, here is link to the documentation lodash.get

edited Jun 19 at 9:29

answered Jun 22 '15 at 8:10

Mr Br

1,489916

UPDATED

I have take comments below into consideration and agreed. Eval is to be avoided.

Accessing root properties in object is easily achieved with obj[variable], but getting nested complicates thing. Not to write already written code I suggest to use lodash.get.

Example

// Accessing root property

var rootProp = 'rootPropert';

_.get(object, rootProp, defaultValue);



// Accessing nested property

var listOfNestedProperties = [var1, var2];

_.get(object, listOfNestedProperties);

Lodash get can be used on different ways, here is link to the documentation lodash.get

edited Jun 19 at 9:29

answered Jun 22 '15 at 8:10

Mr Br

1,489916

edited Jun 19 at 9:29

answered Jun 22 '15 at 8:10

Mr Br

1,489916

answered Jun 22 '15 at 8:10

Mr Br

1,489916

answered Jun 22 '15 at 8:10

Mr Br

1,489916

4

It's best to avoid using eval whenever possible. stackoverflow.com/questions/86513/…
– Luke
Jun 23 '15 at 18:07

7

Using eval for something as trivial as accessing properties is plain overkill and hardly advisable under any circumstance. What's "trouble"? obj['nested']['test'] works very well and doesn't require you to embed code in strings.
– Paul Stenne
Oct 23 '15 at 10:14

3

eval is three times slower or more, I wouldn't recommend this to newbies because it might teach them bad habits. I use obj['nested']['value'] - remember kids, eval is evil!
– jaggedsoft
Nov 26 '15 at 1:25

1

@Luke He's now the only want to bring Lodash _.get to the table. I think this answer deserves now upvotes instead of downvotes. It may be overkill, but it's good to know it exists.
– Emile Bergeron
Dec 20 '16 at 21:42

1

Thank you for introducing lodash for this. I came here by google looking for a method to set a value deep in an object, and used their _.set method (which is identical to above but with the extra arguement for the value to set).
– TPHughes
Jul 3 at 9:03

|
show 3 more comments

4

It's best to avoid using eval whenever possible. stackoverflow.com/questions/86513/…
– Luke
Jun 23 '15 at 18:07

7

Using eval for something as trivial as accessing properties is plain overkill and hardly advisable under any circumstance. What's "trouble"? obj['nested']['test'] works very well and doesn't require you to embed code in strings.
– Paul Stenne
Oct 23 '15 at 10:14

3

eval is three times slower or more, I wouldn't recommend this to newbies because it might teach them bad habits. I use obj['nested']['value'] - remember kids, eval is evil!
– jaggedsoft
Nov 26 '15 at 1:25

1

@Luke He's now the only want to bring Lodash _.get to the table. I think this answer deserves now upvotes instead of downvotes. It may be overkill, but it's good to know it exists.
– Emile Bergeron
Dec 20 '16 at 21:42

1

Thank you for introducing lodash for this. I came here by google looking for a method to set a value deep in an object, and used their _.set method (which is identical to above but with the extra arguement for the value to set).
– TPHughes
Jul 3 at 9:03

It's best to avoid using eval whenever possible. stackoverflow.com/questions/86513/…
– Luke
Jun 23 '15 at 18:07

Using eval for something as trivial as accessing properties is plain overkill and hardly advisable under any circumstance. What's "trouble"? obj['nested']['test'] works very well and doesn't require you to embed code in strings.
– Paul Stenne
Oct 23 '15 at 10:14

eval is three times slower or more, I wouldn't recommend this to newbies because it might teach them bad habits. I use obj['nested']['value'] - remember kids, eval is evil!
– jaggedsoft
Nov 26 '15 at 1:25

@Luke He's now the only want to bring Lodash _.get to the table. I think this answer deserves now upvotes instead of downvotes. It may be overkill, but it's good to know it exists.
– Emile Bergeron
Dec 20 '16 at 21:42

Thank you for introducing lodash for this. I came here by google looking for a method to set a value deep in an object, and used their _.set method (which is identical to above but with the extra arguement for the value to set).
– TPHughes
Jul 3 at 9:03

|
show 3 more comments

up vote
2
down vote

Whenever you need to access property dynamically you have to use square bracket for accessing property not "." operator

Syntax: object[propery}

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

edited Jul 31 at 8:25

Manasi

434314

answered Jul 31 at 8:24

Rupesh Agrawal

632419

add a comment |

up vote
2
down vote

Whenever you need to access property dynamically you have to use square bracket for accessing property not "." operator

Syntax: object[propery}

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

edited Jul 31 at 8:25

Manasi

434314

answered Jul 31 at 8:24

Rupesh Agrawal

632419

add a comment |

up vote
2
down vote

Whenever you need to access property dynamically you have to use square bracket for accessing property not "." operator

Syntax: object[propery}

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

edited Jul 31 at 8:25

Manasi

434314

answered Jul 31 at 8:24

Rupesh Agrawal

632419

Whenever you need to access property dynamically you have to use square bracket for accessing property not "." operator

Syntax: object[propery}

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

const something = { bar: "Foobar!" };

const foo = 'bar';

// something.foo; -- not correct way at it is expecting foo as proprty in  something={ foo: "value"};

// correct way is  something[foo]

alert( something[foo])

edited Jul 31 at 8:25

Manasi

434314

answered Jul 31 at 8:24

Rupesh Agrawal

632419

edited Jul 31 at 8:25

Manasi

434314

edited Jul 31 at 8:25

Manasi

434314

edited Jul 31 at 8:25

Manasi

434314

answered Jul 31 at 8:24

Rupesh Agrawal

632419

answered Jul 31 at 8:24

Rupesh Agrawal

632419

answered Jul 31 at 8:24

Rupesh Agrawal

632419

add a comment |

up vote
2
down vote

You can do it like this using Lodash get

_.get(object, 'a[0].b.c');

edited Sep 6 at 15:57

JJJ

29k147591

answered Sep 6 at 6:36

shalonteoh

2151311

add a comment |

up vote
2
down vote

You can do it like this using Lodash get

_.get(object, 'a[0].b.c');

edited Sep 6 at 15:57

JJJ

29k147591

answered Sep 6 at 6:36

shalonteoh

2151311

add a comment |

up vote
2
down vote

You can do it like this using Lodash get

_.get(object, 'a[0].b.c');

edited Sep 6 at 15:57

JJJ

29k147591

answered Sep 6 at 6:36

shalonteoh

2151311

You can do it like this using Lodash get

_.get(object, 'a[0].b.c');

edited Sep 6 at 15:57

JJJ

29k147591

answered Sep 6 at 6:36

shalonteoh

2151311

edited Sep 6 at 15:57

JJJ

29k147591

edited Sep 6 at 15:57

JJJ

29k147591

edited Sep 6 at 15:57

JJJ

29k147591

answered Sep 6 at 6:36

shalonteoh

2151311

answered Sep 6 at 6:36

shalonteoh

2151311

answered Sep 6 at 6:36

shalonteoh

2151311

add a comment |

up vote
1
down vote

It gets interesting when you have to pass parameters to this function as well.

Code jsfiddle

var obj = {method:function(p1,p2,p3){console.log("method:",arguments)}}



var str = "method('p1', 'p2', 'p3');"



var match = str.match(/^s*(S+)((.*));s*$/);



var func = match[1]

var parameters = match[2].split(',');

for(var i = 0; i < parameters.length; ++i) {

  // clean up param begninning

    parameters[i] = parameters[i].replace(/^s*['"]?/,'');

  // clean up param end

  parameters[i] = parameters[i].replace(/['"]?s*$/,'');

}



obj[func](parameters); // sends parameters as array

obj[func].apply(this, parameters); // sends parameters as individual values

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

add a comment |

up vote
1
down vote

It gets interesting when you have to pass parameters to this function as well.

Code jsfiddle

var obj = {method:function(p1,p2,p3){console.log("method:",arguments)}}



var str = "method('p1', 'p2', 'p3');"



var match = str.match(/^s*(S+)((.*));s*$/);



var func = match[1]

var parameters = match[2].split(',');

for(var i = 0; i < parameters.length; ++i) {

  // clean up param begninning

    parameters[i] = parameters[i].replace(/^s*['"]?/,'');

  // clean up param end

  parameters[i] = parameters[i].replace(/['"]?s*$/,'');

}



obj[func](parameters); // sends parameters as array

obj[func].apply(this, parameters); // sends parameters as individual values

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

add a comment |

up vote
1
down vote

It gets interesting when you have to pass parameters to this function as well.

Code jsfiddle

var obj = {method:function(p1,p2,p3){console.log("method:",arguments)}}



var str = "method('p1', 'p2', 'p3');"



var match = str.match(/^s*(S+)((.*));s*$/);



var func = match[1]

var parameters = match[2].split(',');

for(var i = 0; i < parameters.length; ++i) {

  // clean up param begninning

    parameters[i] = parameters[i].replace(/^s*['"]?/,'');

  // clean up param end

  parameters[i] = parameters[i].replace(/['"]?s*$/,'');

}



obj[func](parameters); // sends parameters as array

obj[func].apply(this, parameters); // sends parameters as individual values

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

It gets interesting when you have to pass parameters to this function as well.

Code jsfiddle

var obj = {method:function(p1,p2,p3){console.log("method:",arguments)}}



var str = "method('p1', 'p2', 'p3');"



var match = str.match(/^s*(S+)((.*));s*$/);



var func = match[1]

var parameters = match[2].split(',');

for(var i = 0; i < parameters.length; ++i) {

  // clean up param begninning

    parameters[i] = parameters[i].replace(/^s*['"]?/,'');

  // clean up param end

  parameters[i] = parameters[i].replace(/['"]?s*$/,'');

}



obj[func](parameters); // sends parameters as array

obj[func].apply(this, parameters); // sends parameters as individual values

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

answered Nov 13 '16 at 17:37

Jacksonkr

17.6k34136234

add a comment |

up vote
-3
down vote

You should use JSON.parse, take a look at https://www.w3schools.com/js/js_json_parse.asp

const obj = JSON.parse('{ "name":"John", "age":30, "city":"New York"}')

console.log(obj.name)

console.log(obj.age)

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

add a comment |

up vote
-3
down vote

You should use JSON.parse, take a look at https://www.w3schools.com/js/js_json_parse.asp

const obj = JSON.parse('{ "name":"John", "age":30, "city":"New York"}')

console.log(obj.name)

console.log(obj.age)

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

add a comment |

up vote
-3
down vote

You should use JSON.parse, take a look at https://www.w3schools.com/js/js_json_parse.asp

const obj = JSON.parse('{ "name":"John", "age":30, "city":"New York"}')

console.log(obj.name)

console.log(obj.age)

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

You should use JSON.parse, take a look at https://www.w3schools.com/js/js_json_parse.asp

const obj = JSON.parse('{ "name":"John", "age":30, "city":"New York"}')

console.log(obj.name)

console.log(obj.age)

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

answered Jun 14 '17 at 21:42

onmyway133

23.8k13153187

add a comment |

up vote
-4
down vote

const something = { bar: "Foobar!" };

const foo = 'bar';



something[`${foo}`];

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

answered Jul 2 '17 at 19:04

Sergey

984

6

Why on earth would you do that? Your foo is already a string, so `${foo}` is exactly the same as foo. (Also, your code seems to have some extra backslashes that don't belong there. But it would still be pointless even if you fixed that syntax error.)
– Ilmari Karonen
Sep 19 '17 at 18:49

add a comment |

up vote
-4
down vote

const something = { bar: "Foobar!" };

const foo = 'bar';



something[`${foo}`];

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

answered Jul 2 '17 at 19:04

Sergey

984

6

Why on earth would you do that? Your foo is already a string, so `${foo}` is exactly the same as foo. (Also, your code seems to have some extra backslashes that don't belong there. But it would still be pointless even if you fixed that syntax error.)
– Ilmari Karonen
Sep 19 '17 at 18:49

add a comment |

up vote
-4
down vote

const something = { bar: "Foobar!" };

const foo = 'bar';



something[`${foo}`];

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

answered Jul 2 '17 at 19:04

Sergey

984

const something = { bar: "Foobar!" };

const foo = 'bar';



something[`${foo}`];

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

answered Jul 2 '17 at 19:04

Sergey

984

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

edited Sep 19 '17 at 17:12

Cody Gray♦

189k34369458

answered Jul 2 '17 at 19:04

Sergey

984

answered Jul 2 '17 at 19:04

Sergey

984

answered Jul 2 '17 at 19:04

Sergey

984

6

Why on earth would you do that? Your foo is already a string, so `${foo}` is exactly the same as foo. (Also, your code seems to have some extra backslashes that don't belong there. But it would still be pointless even if you fixed that syntax error.)
– Ilmari Karonen
Sep 19 '17 at 18:49

add a comment |

6

Why on earth would you do that? Your foo is already a string, so `${foo}` is exactly the same as foo. (Also, your code seems to have some extra backslashes that don't belong there. But it would still be pointless even if you fixed that syntax error.)
– Ilmari Karonen
Sep 19 '17 at 18:49

Why on earth would you do that? Your foo is already a string, so `${foo}` is exactly the same as foo. (Also, your code seems to have some extra backslashes that don't belong there. But it would still be pointless even if you fixed that syntax error.)
– Ilmari Karonen
Sep 19 '17 at 18:49

add a comment |

protected by Samuel Liew♦ Oct 5 '15 at 9:00

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