Question

Using pointers string can be initialized to other characters but when once string has been defined it cannot be initialized to other characters.What is the reason behind it??

int main()
{
char str1[]="hello";
char *p="hello";
str1="bye";/*error*/
p="bye";/*works*/
}

Answer 1

Arrays are arrays and pointers are pointers. Defining arrays gives the pointer to the allocated array, that is a constant pointer to the location where the array space hass been reserved. That is a concrete address in the lifo stack. So, str1 is a constant pointer value and you cannot change it. You cannot set the value of the address of a different constant string.

Defining pointers, as char*p, gives you a variable value of an address. And so, you can change de value of the variable p.