Can I initialize string after declaration?

Question

Can I initialize string after declaration?

char *s;
s = "test";

instead of

char *s = "test"; 

Answer 1

You can, but keep in mind that with that statements you are storing in s a pointer to a read-only string allocated elsewhere. Any attempt to modify it will result in undefined behavior (i.e., on some compilers it may work, but often will just crash). That's why usually you use a const char * for that thing.

Answer 2

Yes, you can.

#include <stdio.h>

int 
main(void)
{
    // `s' is a pointer to `const char' because `s' may point to a string which
    // is in read-only memory.
    char const *s;
    s = "hello";
    puts(s);
    return 0;
}

NB: It doesn't work with arrays.

#include <stdio.h>

int 
main(void)
{
    char s[32];
    s = "hello"; // Syntax error.
    puts(s);
    return 0;
}