const char*

[murva]

Could anybody please explain me the difference between the two following expressions:

char *const p1="John";
char const* p2="Mary";

what is constant in every case, in other words, what can be changed and what cannot be in each case.

Thanks

[kbw]

p2 is a pointer to a constant "Mary"
p2 can change to point to another constant string, but you can't change the value "May" thru p2.

p1 is a constant pointer to "John"
p1 can't change, but you can change "John" thru p1.

[murva]

Thanks, but I'm still confused, the following was accepted by compiler

char const* p2="Mary";
p2="Margareth";

so, I changed the value of p2.

Could you please give me an example and show what could not be changed in this case?
Thanks

[kbw]

char const* p2 = "Mary";
*p2 = 'C'; // not allowed.
p2 = "Margareth";  // allowed

char * const p1 = "John";
*p1 = 'C'; // allowed
p1 = "Margarth"; // not allowed 

[murva]

Thanks, I got it now; very clarifying example