c - const char pointer assignments

Question

Are the following assignments valid? Or will any of these create problems. Please suggest.

const char * c1;  
const char * c2; 
const char * c3;
char * c4;

c2 = c1;
c2 = c3;
c2 = c4;

What if I do the following, is that ok thing to do?

const char * c5 = "xyz";
char * c6 = "abc";

c2 = c5;
c2 = c6;

Answer 1

In your mind draw a line through the asterik. To the left is what is being pointed to and to the right what type of pointer

For example

1. const char * const p - The pointer p is constant and so are the characters that p points to - i.e. cannot change both the pointer and the contents to what p points to
2. const char * p - p points to constant characters. You can change the value of p and get it to point to different constant characters. But whatever p points to, you cannot change the contents.
3. char * const p - You are unable to change the pointer but can change the contents

and finally

1. char * p - Everything is up for grabs

Hope that helps.