A simple memory method for const * and * const and const to modify pointers

We can refer to the practice on item21 in Objective C ++. If const is on the left side of the asterisk, const is used to modify the variable pointed to by the pointer, that is, the pointer points to a constant; if const is on the right side of the asterisk, const modifies the pointer itself, that is, the pointer itself is a constant.

For example:

# Include <iostream>

Using namespace STD;

Int main ()

{

Int A = 3, B = 10;

Int * const Pa = &;

Const int * CPA = &;

// Pa = & B; // Error

CPA = & B;

* PA = 5;

// * CPA = 5; // Error

Return 0;

}

Is it easy?

In fact, even so, I think everyone still needs to memorize it, isn't it? It's very troublesome. Maybe I forget it one day... I can teach you how to learn this experience:

In fact, you only need to remember that the constant string is of the const char * type.

For example:

Const char * P = "xinfanyiluan ";

P = "xinfanyiluan2 ";

// * P = 'D'; // error. The constant cannot be assigned.

Because it is a constant string, its value cannot be changed naturally, right?

Very good, so only one const is displayed, isn't it? It's still on the left of *, isn't it?

Now, you can associate const char * with a constant string:

The pointer is variable, but its pointing value is immutable.

The other case is definitely the opposite, isn't it?

I don't know if you think you don't need to memorize it after learning it like this?