Accessing Array of strings in C Structure

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  1. #1
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    Accessing Array of strings in C Structure

    Hi,

    I'm working on my second C program, but I can't figure out
    how to access the Array of strings in the C Structure below.

    Could someone please show me how ? I'm really lost on this.
    I need to use pointers to access the structure.

    * My code
    Code:
    #include "stdafx.h"
    #include <string.h>
    
    typedef struct st {
    		char *name;
    		int	id;
    		char *items[3];    // MAKE IT AN ARRAY
    };
    
    int _tmain(int argc, _TCHAR* argv[])
    {
    	struct st my_emp;
    	struct st *pmy_emp;
    
                   //ADDED
                  pmy_emp = (struct st *) malloc(sizeof(struct st));
    
    	my_emp.name="Someones Name";
    	my_emp.id = 6;
    	pmy_emp = &my_emp;
    
                    // CHANGED
                    strcat(my_emp.items[0],"Cats");
    	strcat(my_emp.items[1],"Dogs");
    
    	//WAS
                    //pmy_emp->items = "Cats","Dogs";
    
    	printf ("STRUCT TEST...  = %s\n", pmy_emp->name);
    	
    	for(int x=0;x < 2; x++){
    			printf ("ITEMS = %s\n", pmy_emp->items[x]);
    	}
    
    	return 0;
    	}
    END ************

    Thanks,
    -Areal
    Last edited by Areal Person; 05-29-2010 at 07:42 PM.

  2. #2
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    First of all, you don't have any arrays of strings, you have arrays of chars.

    you haven't allocated any memory for the arrays. You need to malloc them some memory before you can use them if you declare then like that (I think). And I don't think you can assign strings like that either, not if they have been malloc'd. Especially the second one - C isn't going to like that comma one bit ^_^. Look into the function:

    malloc - C++ Reference
    strcat - C++ Reference
    Last edited by KBriggs; 05-29-2010 at 07:29 PM.

  3. #3
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    Ok,

    I added a malloc, and used strcat -- but it still bombs ?

    I also made char * items an array - with no luck.

    Any ideas ??

    Thanks much,
    -Areal
    Last edited by Areal Person; 05-29-2010 at 07:43 PM.

  4. #4
    ATH0 quzah's Avatar
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    Code:
    struct foo
    {
        char *arrayofstrings[ 3 ];
    };
    ...
    
    struct foo bar;
    
    bar.arrayofstrings[ 0 ] = malloc( somenumberofcharacters );
    
    ...
    
    strcpy ( bar.arrayofstrings[ 0 ], "hello world" );
    
    ...
    
    printf( "%s\n", bar.arrayofstrings[ 0 ] );
    
    free( bar.arrayofstrings[ 0 ] );

    Quzah.
    Hope is the first step on the road to disappointment.

  5. #5
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    Thanks That did It.

    QUESTION:

    I'm guessing I need to call malloc for each item[element] // Correct ?

    I would just put it in a for loop and use a varaible for each element ?

    Right ?

    Or is there a better way, so I just use one call to malloc ?

  6. #6
    ATH0 quzah's Avatar
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    Yep. A loop is fine. Be sure to free each one as well.


    Quzah.
    Hope is the first step on the road to disappointment.

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