How to use array of pointers to print structure entities?

I wrote a program in C which has a structure named ak.
There is an array of pointers s which stores the address of array p of ak type. After inputting the values, only str is getting printed.

How can I print both str and id using array of pointers?

set 1:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{   

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

        s[i]=&p[i];

        printf("Input string:");

        scanf("%s",&p[i].str);

        printf("Input id:");

        scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

        printf("%sn",s[i].id);

        ++i;

    } 

    return 0;   

}

set 2:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{  

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

         s[i]=&p[i];

         printf("Input string:");

         scanf("%s",&p[i].str);

         printf("Input id:");

         scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

         printf("%sn",s[i]);

         ++i;

    }

    return 0;    

}

So when I tried set1 code,it gave me error saying:

C:CPPcPrototypes>gcc -o ct structure.c

structure.c: In function 'main':

structure.c:22:32: error: request for member 'id' in something not a structure or union



       printf("%sn",*s[i].id);

                          ^

Screenshot is here:

https://imageshack.com/a/img921/3084/j1rHig.png

When I tried set2 code, it only printed str values.
screenshot is here:

https://imageshack.com/a/img922/614/JHSGZ9.png

edited Jan 1 at 15:50

Yunnosch

11.4k52034

asked Jan 1 at 10:14

Athul Krishnan

The error message means you’re using the dot operator where you should be using the arrow operator, or vice versa.

– Jonathan Leffler
Jan 1 at 14:49

Please use Copy&Paste to show us the text error messages. They are no artwork and don't need to be shown as images.

– Gerhardh
Jan 1 at 18:21

the set1 does not compile. How are we to advise you on run-time logic when you do not post code that compiles?

– user3629249
Jan 2 at 0:53

the set2 results in the compiler giving two (serious) warnings: untitled.c:17:18: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=] and untitled.c:24:19: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘ak * {aka struct <anonymous> *}’ [-Wformat=] Both of these problems need to be corrected, or the code will not act as desired when run

– user3629249
Jan 2 at 0:56

OT: the struct definition is missing a 'tag' name. Without a 'tag' name, most debuggers will not display the individual fields in the struct.

– user3629249
Jan 2 at 0:59

|
show 3 more comments

I wrote a program in C which has a structure named ak.
There is an array of pointers s which stores the address of array p of ak type. After inputting the values, only str is getting printed.

How can I print both str and id using array of pointers?

set 1:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{   

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

        s[i]=&p[i];

        printf("Input string:");

        scanf("%s",&p[i].str);

        printf("Input id:");

        scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

        printf("%sn",s[i].id);

        ++i;

    } 

    return 0;   

}

set 2:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{  

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

         s[i]=&p[i];

         printf("Input string:");

         scanf("%s",&p[i].str);

         printf("Input id:");

         scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

         printf("%sn",s[i]);

         ++i;

    }

    return 0;    

}

So when I tried set1 code,it gave me error saying:

C:CPPcPrototypes>gcc -o ct structure.c

structure.c: In function 'main':

structure.c:22:32: error: request for member 'id' in something not a structure or union



       printf("%sn",*s[i].id);

                          ^

Screenshot is here:

https://imageshack.com/a/img921/3084/j1rHig.png

When I tried set2 code, it only printed str values.
screenshot is here:

https://imageshack.com/a/img922/614/JHSGZ9.png

edited Jan 1 at 15:50

Yunnosch

11.4k52034

asked Jan 1 at 10:14

Athul Krishnan

The error message means you’re using the dot operator where you should be using the arrow operator, or vice versa.

– Jonathan Leffler
Jan 1 at 14:49

Please use Copy&Paste to show us the text error messages. They are no artwork and don't need to be shown as images.

– Gerhardh
Jan 1 at 18:21

the set1 does not compile. How are we to advise you on run-time logic when you do not post code that compiles?

– user3629249
Jan 2 at 0:53

the set2 results in the compiler giving two (serious) warnings: untitled.c:17:18: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=] and untitled.c:24:19: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘ak * {aka struct <anonymous> *}’ [-Wformat=] Both of these problems need to be corrected, or the code will not act as desired when run

– user3629249
Jan 2 at 0:56

OT: the struct definition is missing a 'tag' name. Without a 'tag' name, most debuggers will not display the individual fields in the struct.

– user3629249
Jan 2 at 0:59

|
show 3 more comments

I wrote a program in C which has a structure named ak.
There is an array of pointers s which stores the address of array p of ak type. After inputting the values, only str is getting printed.

How can I print both str and id using array of pointers?

set 1:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{   

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

        s[i]=&p[i];

        printf("Input string:");

        scanf("%s",&p[i].str);

        printf("Input id:");

        scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

        printf("%sn",s[i].id);

        ++i;

    } 

    return 0;   

}

set 2:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{  

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

         s[i]=&p[i];

         printf("Input string:");

         scanf("%s",&p[i].str);

         printf("Input id:");

         scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

         printf("%sn",s[i]);

         ++i;

    }

    return 0;    

}

So when I tried set1 code,it gave me error saying:

C:CPPcPrototypes>gcc -o ct structure.c

structure.c: In function 'main':

structure.c:22:32: error: request for member 'id' in something not a structure or union



       printf("%sn",*s[i].id);

                          ^

Screenshot is here:

https://imageshack.com/a/img921/3084/j1rHig.png

When I tried set2 code, it only printed str values.
screenshot is here:

https://imageshack.com/a/img922/614/JHSGZ9.png

edited Jan 1 at 15:50

Yunnosch

11.4k52034

asked Jan 1 at 10:14

Athul Krishnan

I wrote a program in C which has a structure named ak.
There is an array of pointers s which stores the address of array p of ak type. After inputting the values, only str is getting printed.

How can I print both str and id using array of pointers?

set 1:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{   

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

        s[i]=&p[i];

        printf("Input string:");

        scanf("%s",&p[i].str);

        printf("Input id:");

        scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

        printf("%sn",s[i].id);

        ++i;

    } 

    return 0;   

}

set 2:

#include<stdio.h>

typedef struct

{

    char str[10];

    int id;

}ak;



int main()

{  

    printf("Heyn"); 

    int i;

    ak *s[5],p[5];

    for(i=0;i<5;i++)

    {

         s[i]=&p[i];

         printf("Input string:");

         scanf("%s",&p[i].str);

         printf("Input id:");

         scanf("%d",&p[i].id);

    }    

    i=0;

    while(i<5)

    {

         printf("%sn",s[i]);

         ++i;

    }

    return 0;    

}

So when I tried set1 code,it gave me error saying:

C:CPPcPrototypes>gcc -o ct structure.c

structure.c: In function 'main':

structure.c:22:32: error: request for member 'id' in something not a structure or union



       printf("%sn",*s[i].id);

                          ^

Screenshot is here:

https://imageshack.com/a/img921/3084/j1rHig.png

When I tried set2 code, it only printed str values.
screenshot is here:

https://imageshack.com/a/img922/614/JHSGZ9.png

edited Jan 1 at 15:50

Yunnosch

11.4k52034

asked Jan 1 at 10:14

Athul Krishnan

edited Jan 1 at 15:50

Yunnosch

11.4k52034

asked Jan 1 at 10:14

Athul Krishnan

edited Jan 1 at 15:50

Yunnosch

11.4k52034

edited Jan 1 at 15:50

Yunnosch

11.4k52034

edited Jan 1 at 15:50

Yunnosch

11.4k52034

asked Jan 1 at 10:14

Athul Krishnan

asked Jan 1 at 10:14

Athul Krishnan

asked Jan 1 at 10:14

Athul Krishnan

The error message means you’re using the dot operator where you should be using the arrow operator, or vice versa.

– Jonathan Leffler
Jan 1 at 14:49

Please use Copy&Paste to show us the text error messages. They are no artwork and don't need to be shown as images.

– Gerhardh
Jan 1 at 18:21

the set1 does not compile. How are we to advise you on run-time logic when you do not post code that compiles?

– user3629249
Jan 2 at 0:53

the set2 results in the compiler giving two (serious) warnings: untitled.c:17:18: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=] and untitled.c:24:19: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘ak * {aka struct <anonymous> *}’ [-Wformat=] Both of these problems need to be corrected, or the code will not act as desired when run

– user3629249
Jan 2 at 0:56

OT: the struct definition is missing a 'tag' name. Without a 'tag' name, most debuggers will not display the individual fields in the struct.

– user3629249
Jan 2 at 0:59

|
show 3 more comments

The error message means you’re using the dot operator where you should be using the arrow operator, or vice versa.

– Jonathan Leffler
Jan 1 at 14:49

Please use Copy&Paste to show us the text error messages. They are no artwork and don't need to be shown as images.

– Gerhardh
Jan 1 at 18:21

the set1 does not compile. How are we to advise you on run-time logic when you do not post code that compiles?

– user3629249
Jan 2 at 0:53

the set2 results in the compiler giving two (serious) warnings: untitled.c:17:18: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=] and untitled.c:24:19: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘ak * {aka struct <anonymous> *}’ [-Wformat=] Both of these problems need to be corrected, or the code will not act as desired when run

– user3629249
Jan 2 at 0:56

OT: the struct definition is missing a 'tag' name. Without a 'tag' name, most debuggers will not display the individual fields in the struct.

– user3629249
Jan 2 at 0:59

The error message means you’re using the dot operator where you should be using the arrow operator, or vice versa.

– Jonathan Leffler
Jan 1 at 14:49

Please use Copy&Paste to show us the text error messages. They are no artwork and don't need to be shown as images.

– Gerhardh
Jan 1 at 18:21

the set1 does not compile. How are we to advise you on run-time logic when you do not post code that compiles?

– user3629249
Jan 2 at 0:53

the set2 results in the compiler giving two (serious) warnings:

untitled.c:17:18: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=]

and

untitled.c:24:19: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘ak * {aka struct <anonymous> *}’ [-Wformat=]

Both of these problems need to be corrected, or the code will not act as desired when run

– user3629249
Jan 2 at 0:56

the set2 results in the compiler giving two (serious) warnings:

untitled.c:17:18: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘char (*)[10]’ [-Wformat=]

and

untitled.c:24:19: warning: format ‘%s’ expects argument of type ‘char *’, but argument 2 has type ‘ak * {aka struct <anonymous> *}’ [-Wformat=]

Both of these problems need to be corrected, or the code will not act as desired when run

– user3629249
Jan 2 at 0:56

OT: the struct definition is missing a 'tag' name. Without a 'tag' name, most debuggers will not display the individual fields in the struct.

– user3629249
Jan 2 at 0:59

|
show 3 more comments

1 Answer
1

active

oldest

votes

Concerning set1 and your problems with printf("%sn",*s[i].id);.

*s[i].id is equivalent to *(s[i].id), not to (*s[i]).id as you probably supposed. Because the type of s[i] is ak * you cannot get its field id through s[i].id.

You can write (*s[i]).id but a more readable way is to use s[i]->id.

Your printf has an other problem, the format cannot be "%s" because s[i]->id is an int, not a char *

Concerning set2

You do printf("%sn",s[i]);, and you are surprised because only the string is printed, how can you expect that print the string and the int ?

You request to print a string (format %s) but s[i] is not a string. By chance the struct starts by the field str being a string, so yes you write it, but this is not the right way.

You have to explicitly print each attributes, for instance doing printf("%s %dn",s[i]->str, s[i]->id);

edited Jan 2 at 6:13

answered Jan 1 at 10:25

bruno

9,69021126

@AthulKrishnan do you understand the problems ?

– bruno
Jan 1 at 11:06

Got the output....Thank you guyz….

– Athul Krishnan
Jan 2 at 14:56

really....it was a silly mistake...

– Athul Krishnan
Jan 2 at 14:57

add a comment |

Your Answer

StackExchange.ifUsing("editor", function () {
StackExchange.using("externalEditor", function () {
StackExchange.using("snippets", function () {
StackExchange.snippets.init();
});
});
}, "code-snippets");

StackExchange.ready(function() {
var channelOptions = {
tags: "".split(" "),
id: "1"
};
initTagRenderer("".split(" "), "".split(" "), channelOptions);

StackExchange.using("externalEditor", function() {
// Have to fire editor after snippets, if snippets enabled
if (StackExchange.settings.snippets.snippetsEnabled) {
StackExchange.using("snippets", function() {
createEditor();
});
}
else {
createEditor();
}
});

function createEditor() {
StackExchange.prepareEditor({
heartbeatType: 'answer',
autoActivateHeartbeat: false,
convertImagesToLinks: true,
noModals: true,
showLowRepImageUploadWarning: true,
reputationToPostImages: 10,
bindNavPrevention: true,
postfix: "",
imageUploader: {
brandingHtml: "Powered by u003ca class="icon-imgur-white" href="https://imgur.com/"u003eu003c/au003e",
contentPolicyHtml: "User contributions licensed under u003ca href="https://creativecommons.org/licenses/by-sa/3.0/"u003ecc by-sa 3.0 with attribution requiredu003c/au003e u003ca href="https://stackoverflow.com/legal/content-policy"u003e(content policy)u003c/au003e",
allowUrls: true
},
onDemand: true,
discardSelector: ".discard-answer"
,immediatelyShowMarkdownHelp:true
});

}
});

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

StackExchange.ready(
function () {
StackExchange.openid.initPostLogin('.new-post-login', 'https%3a%2f%2fstackoverflow.com%2fquestions%2f53994635%2fhow-to-use-array-of-pointers-to-print-structure-entities%23new-answer', 'question_page');
}
);

Post as a guest

Name

Required, but never shown

1 Answer
1

active

oldest

votes

1 Answer
1

active

oldest

votes

Concerning set1 and your problems with printf("%sn",*s[i].id);.

*s[i].id is equivalent to *(s[i].id), not to (*s[i]).id as you probably supposed. Because the type of s[i] is ak * you cannot get its field id through s[i].id.

You can write (*s[i]).id but a more readable way is to use s[i]->id.

Your printf has an other problem, the format cannot be "%s" because s[i]->id is an int, not a char *

Concerning set2

You do printf("%sn",s[i]);, and you are surprised because only the string is printed, how can you expect that print the string and the int ?

You request to print a string (format %s) but s[i] is not a string. By chance the struct starts by the field str being a string, so yes you write it, but this is not the right way.

You have to explicitly print each attributes, for instance doing printf("%s %dn",s[i]->str, s[i]->id);

edited Jan 2 at 6:13

answered Jan 1 at 10:25

bruno

9,69021126

@AthulKrishnan do you understand the problems ?

– bruno
Jan 1 at 11:06

Got the output....Thank you guyz….

– Athul Krishnan
Jan 2 at 14:56

really....it was a silly mistake...

– Athul Krishnan
Jan 2 at 14:57

add a comment |

Concerning set1 and your problems with printf("%sn",*s[i].id);.

*s[i].id is equivalent to *(s[i].id), not to (*s[i]).id as you probably supposed. Because the type of s[i] is ak * you cannot get its field id through s[i].id.

You can write (*s[i]).id but a more readable way is to use s[i]->id.

Your printf has an other problem, the format cannot be "%s" because s[i]->id is an int, not a char *

Concerning set2

You do printf("%sn",s[i]);, and you are surprised because only the string is printed, how can you expect that print the string and the int ?

You request to print a string (format %s) but s[i] is not a string. By chance the struct starts by the field str being a string, so yes you write it, but this is not the right way.

You have to explicitly print each attributes, for instance doing printf("%s %dn",s[i]->str, s[i]->id);

edited Jan 2 at 6:13

answered Jan 1 at 10:25

bruno

9,69021126

@AthulKrishnan do you understand the problems ?

– bruno
Jan 1 at 11:06

Got the output....Thank you guyz….

– Athul Krishnan
Jan 2 at 14:56

really....it was a silly mistake...

– Athul Krishnan
Jan 2 at 14:57

add a comment |

Concerning set1 and your problems with printf("%sn",*s[i].id);.

*s[i].id is equivalent to *(s[i].id), not to (*s[i]).id as you probably supposed. Because the type of s[i] is ak * you cannot get its field id through s[i].id.

You can write (*s[i]).id but a more readable way is to use s[i]->id.

Your printf has an other problem, the format cannot be "%s" because s[i]->id is an int, not a char *

Concerning set2

You do printf("%sn",s[i]);, and you are surprised because only the string is printed, how can you expect that print the string and the int ?

You request to print a string (format %s) but s[i] is not a string. By chance the struct starts by the field str being a string, so yes you write it, but this is not the right way.

You have to explicitly print each attributes, for instance doing printf("%s %dn",s[i]->str, s[i]->id);

edited Jan 2 at 6:13

answered Jan 1 at 10:25

bruno

9,69021126

Concerning set1 and your problems with printf("%sn",*s[i].id);.

*s[i].id is equivalent to *(s[i].id), not to (*s[i]).id as you probably supposed. Because the type of s[i] is ak * you cannot get its field id through s[i].id.

You can write (*s[i]).id but a more readable way is to use s[i]->id.

Your printf has an other problem, the format cannot be "%s" because s[i]->id is an int, not a char *

Concerning set2

You do printf("%sn",s[i]);, and you are surprised because only the string is printed, how can you expect that print the string and the int ?

You request to print a string (format %s) but s[i] is not a string. By chance the struct starts by the field str being a string, so yes you write it, but this is not the right way.

You have to explicitly print each attributes, for instance doing printf("%s %dn",s[i]->str, s[i]->id);

edited Jan 2 at 6:13

answered Jan 1 at 10:25

bruno

9,69021126

edited Jan 2 at 6:13

answered Jan 1 at 10:25

bruno

9,69021126

answered Jan 1 at 10:25

bruno

9,69021126

answered Jan 1 at 10:25

bruno

9,69021126

@AthulKrishnan do you understand the problems ?

– bruno
Jan 1 at 11:06

Got the output....Thank you guyz….

– Athul Krishnan
Jan 2 at 14:56

really....it was a silly mistake...

– Athul Krishnan
Jan 2 at 14:57

add a comment |

@AthulKrishnan do you understand the problems ?

– bruno
Jan 1 at 11:06

Got the output....Thank you guyz….

– Athul Krishnan
Jan 2 at 14:56

really....it was a silly mistake...

– Athul Krishnan
Jan 2 at 14:57

@AthulKrishnan do you understand the problems ?

– bruno
Jan 1 at 11:06

Got the output....Thank you guyz….

– Athul Krishnan
Jan 2 at 14:56

really....it was a silly mistake...

– Athul Krishnan
Jan 2 at 14:57

add a comment |

draft saved

draft discarded

Thanks for contributing an answer to Stack Overflow!

Please be sure to answer the question. Provide details and share your research!

But avoid …

Asking for help, clarification, or responding to other answers.

Making statements based on opinion; back them up with references or personal experience.

To learn more, see our tips on writing great answers.

draft saved

draft discarded

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Sign up or log in

StackExchange.ready(function () {
StackExchange.helpers.onClickDraftSave('#login-link');
});

Post as a guest

Name

Required, but never shown

Name

Required, but never shown

Name

Required, but never shown

This page is only for reference, If you need detailed information, please check here

Search This Blog

Ufyukyu