What is the difference between char * const and const char *?

Question

What\'s the difference between:

char * const 

and

const char *

Answer 1

Rule of thumb: read the definition from right to left!

---

const int *foo;

Means "foo points (*) to an int that cannot change (const)".
To the programmer this means "I will not change the value of what foo points to".

• *foo = 123; or foo[0] = 123; would be invalid.
• foo = &bar; is allowed.

---

int *const foo;

Means "foo cannot change (const) and points (*) to an int".
To the programmer this means "I will not change the memory address that foo refers to".

• *foo = 123; or foo[0] = 123; is allowed.
• foo = &bar; would be invalid.

---

const int *const foo;

Means "foo cannot change (const) and points (*) to an int that cannot change (const)".
To the programmer this means "I will not change the value of what foo points to, nor will I change the address that foo refers to".

• *foo = 123; or foo[0] = 123; would be invalid.
• foo = &bar; would be invalid.