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cstringcharconstants

What is the difference between char s[] and char *s?

In C, one can use a string literal in a declaration like this:

char s[] = "hello";

or like this:

char *s = "hello";

So what is the difference? I want to know what actually happens in terms of storage duration, both at compile and run time.

Solution

  • The difference here is that 

    char *s = "Hello world";

    will place "Hello world" in the read-only parts of the memory, and making s a pointer to that makes any writing operation on this memory illegal.

    While doing:

    char s[] = "Hello world";

    puts the literal string in read-only memory and copies the string to newly allocated memory on the stack. Thus making

    s[0] = 'J';

    legal.