character pointer

Question

Why this code does not work?

int main(){
  char *str ="abcde";
   scanf("%s",str);
  printf("%s",str);
}

but this works?

int main(){
  char str[] ="abcde";
   scanf("%s",str);
  printf("%s",str);
}`

Answer 1

In the first code, you declare a pointer, which points to a string literal: "abcde".
This might be a constant, and you will not be able to change it.

The second code is declaring an array and filling it with ['a','b',c','d','e','\0'], and is not a constant - so you can change it.

Answer 2

Because char *str ="abcde"; is a pointer to string literal which is most likely stored in read-only memory.

char str[] ="abcde"; is an array initialized with "abcde".

You should also check out Difference between char* and char[]