用途 - 不可更改內容

ex.
const int x = 50;
++x;    <--- error
x=3;    <--- error

const char* a = "abcd";
*a=1;    <--- error
a++;      <--- acceptable

char* const b = "abcd";
*b = 'e'; <--- acceptable
b++;      <--- error

const char* const c = "abcd";
*c = 'e'; <--- error
c++;      <--- error

 

以下為 2-D pointer

char* d[] = {"abcd", "1234"};
const char** e = d;
**e = 'w';  <--- error
*e = "xxx"; <--- acceptable
++e;          <--- acceptable

 

char* d[] = {"abcd", "1234"};
char* const * e = d;
**e = 'w';  <--- acceptable
*e = "xxx"; <--- error
++e;          <--- acceptable

 

char* d[] = {"abcd", "1234"};
char** const e = d;
**e = 'w';  <--- acceptable
*e = "xxx"; <--- acceptable
++e;          <--- error

 

char* d[] = {"abcd", "1234"};
const char* const * const e = d;
**e = 'w';  <--- error
*e = "xxx"; <--- error
++e;          <--- error

 

本文轉載自微風論壇 : http://bbs.wefong.com/viewthread.php?tid=2238225&extra=page%3D1

作者 : cflee3000

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