How to printf all array in C Programming?

Question

i was new with array for C programming. Anybody can help me? I want to print all array that saved from the assignment. Please help!

#include <stdio.h>

int main(){
    const char *a[3];
    char s[100];
    int data, i=0;
    back:
    printf("Please insert name: ");
    scanf(" %s", &s);
    a[i] = s;
    printf("Do you want to add data?: ");
    scanf("%d", &data);
    if (data==1){
        i++;
        goto back;}
    else{
    printf("%s", a[0] , a[1] , a[2]);}
    return 0;
}

You don't check that `i` exceeds the bounds of the `const char *a[3]` array indexing when repeated. — Weather Vane, May 18 '17 at 20:20
Not only that, but all array elements will point to the same string: the most recent entry at `char s[100];`. — Weather Vane, May 18 '17 at 20:22
1) `goto` has it's uses, but this is not a reasonable. 2) Don't get creative with formatting of your code. It already is hard to read; a slightlich more complex code will be unreadable, thus unmaintainable! — too honest for this site, May 18 '17 at 20:48
I know how to use loop and i use goto to make it easier but in here what i saw, the result is still same when use loop and goto. The array doesn't come out. only the last array display for three times. — p1ai, May 19 '17 at 02:50

score 1 · Accepted Answer · edited May 23 '17 at 12:34

My suggestion would be never to use goto statement in C , it really mess up the readability of your source code. Also, go through this link, Why goto statement is not generally used.

Apart from this, you code can be simple re-written like this using for-loop statement.

#include <stdio.h>

int main(){
    char *a[3];
    char s[100];
    int data = 1, i;
    for(i=0; i<3 && data == 1; i++) {
      printf("Please insert name: ");
      scanf(" %s", &s);
      a[i] = s;
      printf("Do you want to add data?: ");
          scanf("%d", &data);
    }
    for(i=0; i<3; i++)
      printf("%s", a[i]);
    return 0;
}

score 0 · Answer 2 · edited May 18 '17 at 20:51

0

#include <stdio.h>
int main()
{
    const char *a[3];
    char s[100];
    int data, i = 0, j;
    back: printf("Please insert name: ");
    scanf(" %s", &s);
    a[i] = s;
    printf("Do you want to add data?: ");
    scanf("%d", &data);
    i++;
    if (data == 1)
    {
        goto back;
    }
    else
    {
        for (j = 0; j < i; j = j + 1)
            printf("%s ", a[j]);
    }
    return 0;
}

edited May 18 '17 at 20:51

mch

9,424
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answered May 18 '17 at 20:32

Ryuuk

89
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3

Yes, the OP used label `back` and `goto back;`, but you shouldn't. – Jonathan Leffler May 18 '17 at 21:50
1

Also: This code is invalid and invokes undefined behaviour for various reasons! Your compiler should be crying, why do you ignore it? (I don't care if the errors are in the original, an answer should provide correct code) – too honest for this site May 19 '17 at 00:17
Also same when using this code, when i print, only the last array appear for three times. – p1ai May 19 '17 at 02:47

How to printf all array in C Programming?

2 Answers2