create object using variables for property name [duplicate]

71

This question already has an answer here:

• 
  How to use a variable for a key in a JavaScript object literal?
  
  11 answers
  
  

Is it at all possible to use variable names in object literal properties for object creation?

Example

function createJSON (propertyName){

    return { propertyName : "Value"};

}



var myObject = createJSON("myProperty");



console.log(myObject.popertyName);  // prints "value"

console.log(myObject.myProperty);  // Does not exist

javascript properties object-literal

share|improve this question

edited Aug 16 '14 at 19:47

Bergi

377k62573903

asked Jun 30 '10 at 22:49

balafibalafi

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Jan 11 '16 at 18:32

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment | 

71

This question already has an answer here:

• 
  How to use a variable for a key in a JavaScript object literal?
  
  11 answers
  
  

Is it at all possible to use variable names in object literal properties for object creation?

Example

function createJSON (propertyName){

    return { propertyName : "Value"};

}



var myObject = createJSON("myProperty");



console.log(myObject.popertyName);  // prints "value"

console.log(myObject.myProperty);  // Does not exist

javascript properties object-literal

share|improve this question

edited Aug 16 '14 at 19:47

Bergi

377k62573903

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

marked as duplicate by Bergi javascript
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Jan 11 '16 at 18:32

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment | 

71

71

71

22

This question already has an answer here:

• 
  How to use a variable for a key in a JavaScript object literal?
  
  11 answers
  
  

Is it at all possible to use variable names in object literal properties for object creation?

Example

function createJSON (propertyName){

    return { propertyName : "Value"};

}



var myObject = createJSON("myProperty");



console.log(myObject.popertyName);  // prints "value"

console.log(myObject.myProperty);  // Does not exist

javascript properties object-literal

share|improve this question

edited Aug 16 '14 at 19:47

Bergi

377k62573903

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

This question already has an answer here:

• 
  How to use a variable for a key in a JavaScript object literal?
  
  11 answers
  
  

Is it at all possible to use variable names in object literal properties for object creation?

Example

function createJSON (propertyName){

    return { propertyName : "Value"};

}



var myObject = createJSON("myProperty");



console.log(myObject.popertyName);  // prints "value"

console.log(myObject.myProperty);  // Does not exist

This question already has an answer here:

• 
  How to use a variable for a key in a JavaScript object literal?
  
  11 answers
  
  

javascript properties object-literal

javascript properties object-literal

share|improve this question

edited Aug 16 '14 at 19:47

Bergi

377k62573903

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

share|improve this question

edited Aug 16 '14 at 19:47

Bergi

377k62573903

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

share|improve this question

share|improve this question

edited Aug 16 '14 at 19:47

Bergi

377k62573903

edited Aug 16 '14 at 19:47

Bergi

377k62573903

edited Aug 16 '14 at 19:47

Bergi

377k62573903

377k62573903

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

asked Jun 30 '10 at 22:49

balafibalafi

1,2001818

1,2001818

marked as duplicate by Bergi javascript
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Jan 11 '16 at 18:32

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marked as duplicate by Bergi javascript
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Jan 11 '16 at 18:32

This question has been asked before and already has an answer. If those answers do not fully address your question, please ask a new question.

add a comment | 

add a comment | 

4 Answers
4

active

oldest

votes

143

If, in ES6, you want to use a variable for a property name, you can use the new ComputedPropertyName syntax. Place the variable name between square brackets:

var foo = "bar";

var ob  = { [foo]: "something" }; // ob.bar === "something"

In ES5, you have to create the object first, and then add the property using square bracket notation.

var foo = "bar";

var ob  = {};

ob[foo] = "something"; // === ob.bar = "something"

If you wanted to programatically create JSON, you would have to serialize the object to a string conforming to the JSON format. e.g. with the JSON.stringify method.

share|improve this answer

edited Dec 18 '17 at 9:13

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

add a comment | 

38

ES6 introduces computed property names, which allow you to do

function CreateJSON (propertyName){

    var myObject = { [propertyName] : "Value"};

}

Note browser support is currently negligible.

share|improve this answer

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  interesting, any updates on browser support?
  
  – Ayyash
  Apr 15 '15 at 7:46
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.
  
  – Oriol
  Apr 15 '15 at 15:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This is the best answer for me. I'm using nodejs.
  
  – James
  Feb 17 '16 at 12:45
  

  
  
  
  

add a comment | 

7

You can sort of do this:

  var myObject = {};

  CreateProp("myProperty","MyValue");



  function CreateProp(propertyName, propertyValue)

  {

      myObject[propertyName] = propertyValue;

      alert(myObject[propertyName]);  // prints "MyValue" 

  };

I much perfer this syntax myself though:

function jsonObject()

{

};

var myNoteObject = new jsonObject();



function SaveJsonObject()

{

    myNoteObject.Control = new jsonObject();

    myNoteObject.Control.Field1= "Fred";

    myNoteObject.Control.Field2= "Wilma";

    myNoteObject.Control.Field3= "Flintstone";

    myNoteObject.Control.Id= "1234";

    myNoteObject.Other= new jsonObject();

    myNoteObject.Other.One="myone";

};

Then you can use the following:

SaveJsonObject();

var myNoteJSON = JSON.stringify(myNoteObject);

NOTE: This makes use of the json2.js from here:http://www.json.org/js.html

share|improve this answer

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

add a comment | 

5

One thing that may be suitable (now that JSON functionality is common to newer browsers, and json2.js is a perfectly valid fallback), is to construct a JSON string and then parse it.

function func(prop, val) {

    var jsonStr = '{"'+prop+'":'+val+'}';

    return JSON.parse(jsonStr);

}



var testa = func("init", 1);

console.log(testa.init);//1

Just keep in mind, JSON property names need to be enclosed in double quotes.

share|improve this answer

answered Jan 6 '12 at 2:19

ChaseChase

195210

add a comment | 

4 Answers
4

active

oldest

votes

4 Answers
4

active

oldest

votes

active

oldest

votes

active

oldest

votes

143

If, in ES6, you want to use a variable for a property name, you can use the new ComputedPropertyName syntax. Place the variable name between square brackets:

var foo = "bar";

var ob  = { [foo]: "something" }; // ob.bar === "something"

In ES5, you have to create the object first, and then add the property using square bracket notation.

var foo = "bar";

var ob  = {};

ob[foo] = "something"; // === ob.bar = "something"

If you wanted to programatically create JSON, you would have to serialize the object to a string conforming to the JSON format. e.g. with the JSON.stringify method.

share|improve this answer

edited Dec 18 '17 at 9:13

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

add a comment | 

143

If, in ES6, you want to use a variable for a property name, you can use the new ComputedPropertyName syntax. Place the variable name between square brackets:

var foo = "bar";

var ob  = { [foo]: "something" }; // ob.bar === "something"

In ES5, you have to create the object first, and then add the property using square bracket notation.

var foo = "bar";

var ob  = {};

ob[foo] = "something"; // === ob.bar = "something"

If you wanted to programatically create JSON, you would have to serialize the object to a string conforming to the JSON format. e.g. with the JSON.stringify method.

share|improve this answer

edited Dec 18 '17 at 9:13

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

add a comment | 

143

143

143

If, in ES6, you want to use a variable for a property name, you can use the new ComputedPropertyName syntax. Place the variable name between square brackets:

var foo = "bar";

var ob  = { [foo]: "something" }; // ob.bar === "something"

In ES5, you have to create the object first, and then add the property using square bracket notation.

var foo = "bar";

var ob  = {};

ob[foo] = "something"; // === ob.bar = "something"

If you wanted to programatically create JSON, you would have to serialize the object to a string conforming to the JSON format. e.g. with the JSON.stringify method.

share|improve this answer

edited Dec 18 '17 at 9:13

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

If, in ES6, you want to use a variable for a property name, you can use the new ComputedPropertyName syntax. Place the variable name between square brackets:

var foo = "bar";

var ob  = { [foo]: "something" }; // ob.bar === "something"

In ES5, you have to create the object first, and then add the property using square bracket notation.

var foo = "bar";

var ob  = {};

ob[foo] = "something"; // === ob.bar = "something"

If you wanted to programatically create JSON, you would have to serialize the object to a string conforming to the JSON format. e.g. with the JSON.stringify method.

share|improve this answer

edited Dec 18 '17 at 9:13

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

share|improve this answer

share|improve this answer

edited Dec 18 '17 at 9:13

edited Dec 18 '17 at 9:13

edited Dec 18 '17 at 9:13

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

answered Jun 30 '10 at 22:51

QuentinQuentin

653k728871051

653k728871051

add a comment | 

add a comment | 

38

ES6 introduces computed property names, which allow you to do

function CreateJSON (propertyName){

    var myObject = { [propertyName] : "Value"};

}

Note browser support is currently negligible.

share|improve this answer

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  interesting, any updates on browser support?
  
  – Ayyash
  Apr 15 '15 at 7:46
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.
  
  – Oriol
  Apr 15 '15 at 15:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This is the best answer for me. I'm using nodejs.
  
  – James
  Feb 17 '16 at 12:45
  

  
  
  
  

add a comment | 

38

ES6 introduces computed property names, which allow you to do

function CreateJSON (propertyName){

    var myObject = { [propertyName] : "Value"};

}

Note browser support is currently negligible.

share|improve this answer

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  interesting, any updates on browser support?
  
  – Ayyash
  Apr 15 '15 at 7:46
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.
  
  – Oriol
  Apr 15 '15 at 15:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This is the best answer for me. I'm using nodejs.
  
  – James
  Feb 17 '16 at 12:45
  

  
  
  
  

add a comment | 

38

38

38

ES6 introduces computed property names, which allow you to do

function CreateJSON (propertyName){

    var myObject = { [propertyName] : "Value"};

}

Note browser support is currently negligible.

share|improve this answer

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

ES6 introduces computed property names, which allow you to do

function CreateJSON (propertyName){

    var myObject = { [propertyName] : "Value"};

}

Note browser support is currently negligible.

share|improve this answer

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

share|improve this answer

share|improve this answer

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

answered Aug 15 '14 at 19:48

OriolOriol

161k38268374

161k38268374

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  interesting, any updates on browser support?
  
  – Ayyash
  Apr 15 '15 at 7:46
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.
  
  – Oriol
  Apr 15 '15 at 15:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This is the best answer for me. I'm using nodejs.
  
  – James
  Feb 17 '16 at 12:45
  

  
  
  
  

add a comment | 

• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  interesting, any updates on browser support?
  
  – Ayyash
  Apr 15 '15 at 7:46
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.
  
  – Oriol
  Apr 15 '15 at 15:20
  

  
  
  
  


• 
  
  
  

  
  

  
  
  
  
  
  

  
  
  This is the best answer for me. I'm using nodejs.
  
  – James
  Feb 17 '16 at 12:45
  

  
  
  
  

interesting, any updates on browser support?

– Ayyash
Apr 15 '15 at 7:46

interesting, any updates on browser support?

– Ayyash
Apr 15 '15 at 7:46

When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.

– Oriol
Apr 15 '15 at 15:20

When I wrote the answer, only Firefox Nigthly. Now Firefox 34+ and Safari 7.1.3+, according to MDN.

– Oriol
Apr 15 '15 at 15:20

This is the best answer for me. I'm using nodejs.

– James
Feb 17 '16 at 12:45

This is the best answer for me. I'm using nodejs.

– James
Feb 17 '16 at 12:45

add a comment | 

7

You can sort of do this:

  var myObject = {};

  CreateProp("myProperty","MyValue");



  function CreateProp(propertyName, propertyValue)

  {

      myObject[propertyName] = propertyValue;

      alert(myObject[propertyName]);  // prints "MyValue" 

  };

I much perfer this syntax myself though:

function jsonObject()

{

};

var myNoteObject = new jsonObject();



function SaveJsonObject()

{

    myNoteObject.Control = new jsonObject();

    myNoteObject.Control.Field1= "Fred";

    myNoteObject.Control.Field2= "Wilma";

    myNoteObject.Control.Field3= "Flintstone";

    myNoteObject.Control.Id= "1234";

    myNoteObject.Other= new jsonObject();

    myNoteObject.Other.One="myone";

};

Then you can use the following:

SaveJsonObject();

var myNoteJSON = JSON.stringify(myNoteObject);

NOTE: This makes use of the json2.js from here:http://www.json.org/js.html

share|improve this answer

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

add a comment | 

7

You can sort of do this:

  var myObject = {};

  CreateProp("myProperty","MyValue");



  function CreateProp(propertyName, propertyValue)

  {

      myObject[propertyName] = propertyValue;

      alert(myObject[propertyName]);  // prints "MyValue" 

  };

I much perfer this syntax myself though:

function jsonObject()

{

};

var myNoteObject = new jsonObject();



function SaveJsonObject()

{

    myNoteObject.Control = new jsonObject();

    myNoteObject.Control.Field1= "Fred";

    myNoteObject.Control.Field2= "Wilma";

    myNoteObject.Control.Field3= "Flintstone";

    myNoteObject.Control.Id= "1234";

    myNoteObject.Other= new jsonObject();

    myNoteObject.Other.One="myone";

};

Then you can use the following:

SaveJsonObject();

var myNoteJSON = JSON.stringify(myNoteObject);

NOTE: This makes use of the json2.js from here:http://www.json.org/js.html

share|improve this answer

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

add a comment | 

7

7

7

You can sort of do this:

  var myObject = {};

  CreateProp("myProperty","MyValue");



  function CreateProp(propertyName, propertyValue)

  {

      myObject[propertyName] = propertyValue;

      alert(myObject[propertyName]);  // prints "MyValue" 

  };

I much perfer this syntax myself though:

function jsonObject()

{

};

var myNoteObject = new jsonObject();



function SaveJsonObject()

{

    myNoteObject.Control = new jsonObject();

    myNoteObject.Control.Field1= "Fred";

    myNoteObject.Control.Field2= "Wilma";

    myNoteObject.Control.Field3= "Flintstone";

    myNoteObject.Control.Id= "1234";

    myNoteObject.Other= new jsonObject();

    myNoteObject.Other.One="myone";

};

Then you can use the following:

SaveJsonObject();

var myNoteJSON = JSON.stringify(myNoteObject);

NOTE: This makes use of the json2.js from here:http://www.json.org/js.html

share|improve this answer

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

You can sort of do this:

  var myObject = {};

  CreateProp("myProperty","MyValue");



  function CreateProp(propertyName, propertyValue)

  {

      myObject[propertyName] = propertyValue;

      alert(myObject[propertyName]);  // prints "MyValue" 

  };

I much perfer this syntax myself though:

function jsonObject()

{

};

var myNoteObject = new jsonObject();



function SaveJsonObject()

{

    myNoteObject.Control = new jsonObject();

    myNoteObject.Control.Field1= "Fred";

    myNoteObject.Control.Field2= "Wilma";

    myNoteObject.Control.Field3= "Flintstone";

    myNoteObject.Control.Id= "1234";

    myNoteObject.Other= new jsonObject();

    myNoteObject.Other.One="myone";

};

Then you can use the following:

SaveJsonObject();

var myNoteJSON = JSON.stringify(myNoteObject);

NOTE: This makes use of the json2.js from here:http://www.json.org/js.html

share|improve this answer

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

share|improve this answer

share|improve this answer

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

answered Jul 1 '10 at 20:19

Mark SchultheissMark Schultheiss

24.2k85283

24.2k85283

add a comment | 

add a comment | 

5

One thing that may be suitable (now that JSON functionality is common to newer browsers, and json2.js is a perfectly valid fallback), is to construct a JSON string and then parse it.

function func(prop, val) {

    var jsonStr = '{"'+prop+'":'+val+'}';

    return JSON.parse(jsonStr);

}



var testa = func("init", 1);

console.log(testa.init);//1

Just keep in mind, JSON property names need to be enclosed in double quotes.

share|improve this answer

answered Jan 6 '12 at 2:19

ChaseChase

195210

add a comment | 

5

One thing that may be suitable (now that JSON functionality is common to newer browsers, and json2.js is a perfectly valid fallback), is to construct a JSON string and then parse it.

function func(prop, val) {

    var jsonStr = '{"'+prop+'":'+val+'}';

    return JSON.parse(jsonStr);

}



var testa = func("init", 1);

console.log(testa.init);//1

Just keep in mind, JSON property names need to be enclosed in double quotes.

share|improve this answer

answered Jan 6 '12 at 2:19

ChaseChase

195210

add a comment | 

5

5

5

One thing that may be suitable (now that JSON functionality is common to newer browsers, and json2.js is a perfectly valid fallback), is to construct a JSON string and then parse it.

function func(prop, val) {

    var jsonStr = '{"'+prop+'":'+val+'}';

    return JSON.parse(jsonStr);

}



var testa = func("init", 1);

console.log(testa.init);//1

Just keep in mind, JSON property names need to be enclosed in double quotes.

share|improve this answer

answered Jan 6 '12 at 2:19

ChaseChase

195210

One thing that may be suitable (now that JSON functionality is common to newer browsers, and json2.js is a perfectly valid fallback), is to construct a JSON string and then parse it.

function func(prop, val) {

    var jsonStr = '{"'+prop+'":'+val+'}';

    return JSON.parse(jsonStr);

}



var testa = func("init", 1);

console.log(testa.init);//1

Just keep in mind, JSON property names need to be enclosed in double quotes.

share|improve this answer

answered Jan 6 '12 at 2:19

ChaseChase

195210

share|improve this answer

share|improve this answer

answered Jan 6 '12 at 2:19

ChaseChase

195210

answered Jan 6 '12 at 2:19

ChaseChase

195210

answered Jan 6 '12 at 2:19

ChaseChase

195210

195210

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