char pointer initialization in C

Question

I am not so clear on character pointer and how they work.

The program builds, but crashes when I run it.

 char *ab = NULL;
 //ab = \"abc123\"; // works f         


        

Answer 1

"ab" is null and sprintf is trying to write to it, you have to allocate it first.

char ab[20];

sprintf(ab, "abc%d", 123); //

or

char * ab = malloc(20); // new, whatever

sprintf(ab, "abc%d", 123); //