expected output and the practical output not matching, please explain the logic behind the code

    #include<stdio.h>



    int main()



    {



    char *str = {"Frogs","Do","Not","Die.","They","Croak"};



    printf("%c %c %c",*str[0],*str[1],*str[2]);//expected F D N



    printf("n%u %u %u",str[0],str[1],str[2]);//expected 1000 1006 1003



   }

this output is based on the assumption that froak begins at 1000

the output is as follows

F D N



2162395060 2162395057 2162395053

how can that be possible, here the address is decreasing for str[0] to str[2], printing the address of str[3], str[4], str[5], shows no pattern and rather have abrupt changes in the addresses

edited Nov 20 '18 at 13:05

Dennis Vash

609317

asked Nov 20 '18 at 12:28

rishabh jain

285

4

The compiler may place literal strings anywhere it pleases. There doesn't even have to be a pattern that the location is increasing only.

– Some programmer dude
Nov 20 '18 at 12:38

2

On a slightly related note, to use printf to print pointers, use the format specifier "%p" to print void * pointers (and you really should cast the pointers). The "%u" format expects unsigned int arguments, and pointers aren't unsigned int (and may not even be the same size).

– Some programmer dude
Nov 20 '18 at 12:39

1

Does it really matter, or it is just for curiosity?

– Cid
Nov 20 '18 at 12:41

2

On a slightly unrelated note, what reasoning could you have to expect 1000 1006 1003 as the addresses? There are lots of things wrong with those three numbers.

– usr2564301
Nov 20 '18 at 12:42

1

@Cid it was only for curiosity because right now I am learning pointers in c

– rishabh jain
Nov 20 '18 at 13:04

|
show 4 more comments

    #include<stdio.h>



    int main()



    {



    char *str = {"Frogs","Do","Not","Die.","They","Croak"};



    printf("%c %c %c",*str[0],*str[1],*str[2]);//expected F D N



    printf("n%u %u %u",str[0],str[1],str[2]);//expected 1000 1006 1003



   }

this output is based on the assumption that froak begins at 1000

the output is as follows

F D N



2162395060 2162395057 2162395053

edited Nov 20 '18 at 13:05

Dennis Vash

609317

asked Nov 20 '18 at 12:28

rishabh jain

285

4

The compiler may place literal strings anywhere it pleases. There doesn't even have to be a pattern that the location is increasing only.

– Some programmer dude
Nov 20 '18 at 12:38

2

On a slightly related note, to use printf to print pointers, use the format specifier "%p" to print void * pointers (and you really should cast the pointers). The "%u" format expects unsigned int arguments, and pointers aren't unsigned int (and may not even be the same size).

– Some programmer dude
Nov 20 '18 at 12:39

1

Does it really matter, or it is just for curiosity?

– Cid
Nov 20 '18 at 12:41

2

On a slightly unrelated note, what reasoning could you have to expect 1000 1006 1003 as the addresses? There are lots of things wrong with those three numbers.

– usr2564301
Nov 20 '18 at 12:42

1

@Cid it was only for curiosity because right now I am learning pointers in c

– rishabh jain
Nov 20 '18 at 13:04

|
show 4 more comments

    #include<stdio.h>



    int main()



    {



    char *str = {"Frogs","Do","Not","Die.","They","Croak"};



    printf("%c %c %c",*str[0],*str[1],*str[2]);//expected F D N



    printf("n%u %u %u",str[0],str[1],str[2]);//expected 1000 1006 1003



   }

this output is based on the assumption that froak begins at 1000

the output is as follows

F D N



2162395060 2162395057 2162395053

edited Nov 20 '18 at 13:05

Dennis Vash

609317

asked Nov 20 '18 at 12:28

rishabh jain

285

    #include<stdio.h>



    int main()



    {



    char *str = {"Frogs","Do","Not","Die.","They","Croak"};



    printf("%c %c %c",*str[0],*str[1],*str[2]);//expected F D N



    printf("n%u %u %u",str[0],str[1],str[2]);//expected 1000 1006 1003



   }

this output is based on the assumption that froak begins at 1000

the output is as follows

F D N



2162395060 2162395057 2162395053

c arrays string pointers c-strings

edited Nov 20 '18 at 13:05

Dennis Vash

609317

asked Nov 20 '18 at 12:28

rishabh jain

285

edited Nov 20 '18 at 13:05

Dennis Vash

609317

asked Nov 20 '18 at 12:28

rishabh jain

285

edited Nov 20 '18 at 13:05

Dennis Vash

609317

edited Nov 20 '18 at 13:05

Dennis Vash

609317

edited Nov 20 '18 at 13:05

Dennis Vash

609317

asked Nov 20 '18 at 12:28

rishabh jain

285

asked Nov 20 '18 at 12:28

rishabh jain

285

asked Nov 20 '18 at 12:28

rishabh jain

285

4

The compiler may place literal strings anywhere it pleases. There doesn't even have to be a pattern that the location is increasing only.

– Some programmer dude
Nov 20 '18 at 12:38

2

On a slightly related note, to use printf to print pointers, use the format specifier "%p" to print void * pointers (and you really should cast the pointers). The "%u" format expects unsigned int arguments, and pointers aren't unsigned int (and may not even be the same size).

– Some programmer dude
Nov 20 '18 at 12:39

1

Does it really matter, or it is just for curiosity?

– Cid
Nov 20 '18 at 12:41

2

On a slightly unrelated note, what reasoning could you have to expect 1000 1006 1003 as the addresses? There are lots of things wrong with those three numbers.

– usr2564301
Nov 20 '18 at 12:42

1

@Cid it was only for curiosity because right now I am learning pointers in c

– rishabh jain
Nov 20 '18 at 13:04

|
show 4 more comments

4

The compiler may place literal strings anywhere it pleases. There doesn't even have to be a pattern that the location is increasing only.

– Some programmer dude
Nov 20 '18 at 12:38

2

On a slightly related note, to use printf to print pointers, use the format specifier "%p" to print void * pointers (and you really should cast the pointers). The "%u" format expects unsigned int arguments, and pointers aren't unsigned int (and may not even be the same size).

– Some programmer dude
Nov 20 '18 at 12:39

1

Does it really matter, or it is just for curiosity?

– Cid
Nov 20 '18 at 12:41

2

On a slightly unrelated note, what reasoning could you have to expect 1000 1006 1003 as the addresses? There are lots of things wrong with those three numbers.

– usr2564301
Nov 20 '18 at 12:42

1

@Cid it was only for curiosity because right now I am learning pointers in c

– rishabh jain
Nov 20 '18 at 13:04

The compiler may place literal strings anywhere it pleases. There doesn't even have to be a pattern that the location is increasing only.

– Some programmer dude
Nov 20 '18 at 12:38

On a slightly related note, to use printf to print pointers, use the format specifier "%p" to print void * pointers (and you really should cast the pointers). The "%u" format expects unsigned int arguments, and pointers aren't unsigned int (and may not even be the same size).

– Some programmer dude
Nov 20 '18 at 12:39

Does it really matter, or it is just for curiosity?

– Cid
Nov 20 '18 at 12:41

On a slightly unrelated note, what reasoning could you have to expect 1000 1006 1003 as the addresses? There are lots of things wrong with those three numbers.

– usr2564301
Nov 20 '18 at 12:42

@Cid it was only for curiosity because right now I am learning pointers in c

– rishabh jain
Nov 20 '18 at 13:04

|
show 4 more comments

1 Answer
1

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You are printing the addresses of three string constants. The compiler is under no obligation to organize the string constants in any predictable fashion.

The compiler is required to provide an array of pointers. The array can be accessed sequentially to obtain addresses of the string constants, but the string constants may be stored in any location which the compiler deems efficient or useful.

I ran the same code on mac OS using AppleClang 10.0.0.10001044 and got the following output:

F D N

104431486 104431492 104431495

As you can see, the pointers are sequential using AppleClang.

However, that is irrelevant. Nothing in your code should depend on how the compiler chooses to allocate memory for the string constants.

answered Nov 20 '18 at 12:40

John Murray

809514

add a comment |

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You are printing the addresses of three string constants. The compiler is under no obligation to organize the string constants in any predictable fashion.

I ran the same code on mac OS using AppleClang 10.0.0.10001044 and got the following output:

F D N

104431486 104431492 104431495

As you can see, the pointers are sequential using AppleClang.

However, that is irrelevant. Nothing in your code should depend on how the compiler chooses to allocate memory for the string constants.

answered Nov 20 '18 at 12:40

John Murray

809514

add a comment |

You are printing the addresses of three string constants. The compiler is under no obligation to organize the string constants in any predictable fashion.

I ran the same code on mac OS using AppleClang 10.0.0.10001044 and got the following output:

F D N

104431486 104431492 104431495

As you can see, the pointers are sequential using AppleClang.

However, that is irrelevant. Nothing in your code should depend on how the compiler chooses to allocate memory for the string constants.

answered Nov 20 '18 at 12:40

John Murray

809514

add a comment |

You are printing the addresses of three string constants. The compiler is under no obligation to organize the string constants in any predictable fashion.

I ran the same code on mac OS using AppleClang 10.0.0.10001044 and got the following output:

F D N

104431486 104431492 104431495

As you can see, the pointers are sequential using AppleClang.

However, that is irrelevant. Nothing in your code should depend on how the compiler chooses to allocate memory for the string constants.

answered Nov 20 '18 at 12:40

John Murray

809514

You are printing the addresses of three string constants. The compiler is under no obligation to organize the string constants in any predictable fashion.

I ran the same code on mac OS using AppleClang 10.0.0.10001044 and got the following output:

F D N

104431486 104431492 104431495

As you can see, the pointers are sequential using AppleClang.

However, that is irrelevant. Nothing in your code should depend on how the compiler chooses to allocate memory for the string constants.

answered Nov 20 '18 at 12:40

John Murray

809514

answered Nov 20 '18 at 12:40

John Murray

809514

answered Nov 20 '18 at 12:40

John Murray

809514

answered Nov 20 '18 at 12:40

John Murray

809514

add a comment |

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