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

Unlike in Java or other higher level languages, many of the C library's string functions don't simply set a string reference, instead they operate on a block of pre-allocated memory called a character array.

Your first line is saying that ab points to a non-existent memory location.

You'd have more luck if, instead of char *ab = NULL; you did either:

char ab[12];

or:

char *ab = (char*)malloc(12);