segmentation fault (core dumped) when changing string characters

Question

Why changing string characters causes segmentation fault(core dumped):

char *str = \"string\";
str[0] = \'S\'; //segmentation fault(core dumped) 

Answer 1

The solution is simple, declare your string in the following way instead

  char str[] = "string";

The reason why you should do this is because of the Undefined behavior. Creating a string with pointers will make your string locate at the read only memory part, so you cannot modify it, whereas another way will also make a copy of your string on the stack. Also check What is the difference between char s[] and char *s in C?