C - snprintf(char*, size, “%d”, int) Changes Value of Int to 10

Question

Consider this short function:

char* arr(char c, char* m) {
int i;
size_t size = strlen(m);
char* arrs = malloc(size);

i = (int) c;
// outputs 100 if c == “d”
printf(“%d”, i);
snprintf(arrs, size, “%d”, i);
// outputs 10 if c == “d”
printf(“%s”, arrs);

free(arrs);
return (arrs);
}

Why is it that if the input (char c) is the letter “d”, it converts to ASCII int correctly (100), but using snprintf to convert char c to char* m outputs 10?

Answer 1

Of course two minutes after I posted this, I realized I wasn’t accounting for the null terminator at the end of the string. Nevermind! Thanks anyway guys!