Array of int to string conversion in C

Question

I'm trying to convert an array of integers into a string in C. FOr instance I have the following code:

 int number[] = {1,3,2,0};
 char c[5];
 for(int i = 0 ; i < 4; i ++ ){
        c[i] = number[i];
    }
printf("%s", c);

It however outputs smiley faces or hearts and I am not sure why.

score 0 · Answer 1 · answered Dec 28 '21 at 17:10

0

When you printf characters, it takes the ASCII symbol for that number.

Your numbers 1, 3, 2, 0 are SOH, ETX, STX, which are non-printable characters.

Try the numbers 65, 66 for example, they are letters.

answered Dec 28 '21 at 17:10

Bart Friederichs

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0___________ · Answer 2 · 2021-12-28T17:25:09.993

0

The code shown is not giving you any output as it will not compile.

It is hard to say what you want to archive but here you have an example:

int main(void)
{
    int number[] = {1,3,2,0};
    char c[sizeof(number) / sizeof(number[0]) + 1] = {0,};
    char d[sizeof(number) / sizeof(number[0])][10];

    for(int i = 0 ; i < 4; i ++ ){
        c[i] = number[i] % 10 + '0';
        snprintf(d[i], 10, "%d", number[i]);
    }
    printf("%s\n", c);

    for(int i = 0 ; i < 4; i ++ ){
        printf("%s\n",d[i]);
    }

}

edited Dec 28 '21 at 17:25

answered Dec 28 '21 at 17:16

0___________

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Can you extract `sizeof(number) / sizeof(number[0]` into a `numberSize` and reuse it, or does it have to be a compile time constant? – Alexander Dec 28 '21 at 17:23
@Alexander does it matter in this example? – 0___________ Dec 28 '21 at 17:24
1

Magic number 10 in `char d[sizeof(number) / sizeof(number[0])][10];` deserves a comment. I'd expect 12 to handle all 32-bit `int`. – chux - Reinstate Monica Dec 28 '21 at 17:38

Array of int to string conversion in C

2 Answers2