C + + CONST Keyword Summary

1. The const modifier variable, which indicates that the value of the variable does not change:

Const TYPE ValueName = value;

2. The pointer uses the const

(1) The pointer itself is constant, with the following two types of notation:

(char*) const pName;

(2) The pointer points to the content is constant, there are the following two ways:

(char) const *pname;

Const (char) *pname;

(3) both are not changed

const char* Const pName;

3. const modifier Function parameters

Parameters cannot be changed within a function: void function( const intVar);

The content pointed to by the parameter pointer cannot be changed within the function: void function( constchar* Var);

The parameter pointer itself is a constant that cannot be changed: void function( char * constVar);

Parameters are references that increase efficiency while preventing modification: void function( constTYPE& Var);

4. const modifier function return value

const int* fun2(),调用时const int *pValue = fun2();//我们可以把fun2()看作成一个变量，即指针内容不可变

  int * const fun3(), 调用时int * const pValue = fun2();We can think of fun2 () as a variable, that is, the pointer itself is not mutable

C + + CONST Keyword Summary