question about C const

Question

Possible Duplicate:
about “int const *p” and “const int *p ”

Difference between

const  char *p

and

char * const p?

is that fist one means cannot change char. Later one means cannot change the pointer. Am I right? Thank you!

Not an exact duplicate, but close enough that it should answer your question. — Matt K, Mar 11 '11 at 22:13
Just read them backwards: "p is a pointer to a char that is constant", "p is a constant pointer to a char". — Jim Balter, Mar 11 '11 at 22:44
@ikegami No, it doesn't. "p is a pointer to a constant char" and "p is a pointer to a char that is constant" mean the same thing and so do the declarations. — Jim Balter, Mar 12 '11 at 06:57

ikegami · Accepted Answer · 2011-03-11T22:23:07.337

10

const char *p

means the characters cannot be changed. *p = '\0' is illegal. Var p is a pointer to a const char.

char * const p

means the pointer cannot be changed. p = 0 is illegal. Constant p is a pointer to a char.

const char * const p

means neither can be changed. Constant p is a pointer to a const char.

Update: Added third declaration.

edited Mar 11 '11 at 22:23

answered Mar 11 '11 at 22:14

ikegami

score 3 · Answer 2 · answered Mar 11 '11 at 22:14

3

In the first you can't edit the pointee and in the second you can't edit the pointer. Have a look at this perhaps.

answered Mar 11 '11 at 22:14

Morten Kristensen

2 Answers2