标签：c++
在类中的const基本有三种用法
const int func(); // 返回值是const类型
int func(const int); // 参数为const类型
int func(int )const; // 为const类型的成员函数，只能调用类中const类型的变量；
另外，当类的实例是const类型时，也只能调用类中的const成员函数，且只有类的成员函数才能被修饰为const类型；
//Point.h
#include <iostream>
using namespace std;
class Point{
private:
int x,y;
public:
Point(int a,int b){
x=a;y=b;
cout<<"Point constructor is called !\n";
};
~Point(){
cout<<"Point destructor is called !\n";
}
public:
const int getX(){
return x;
}
const int getY(){
return y;
}
public:
void setX(const int a,int b) {
x=a;y=b;
}
public:
void printPoint() const{
cout<<"const type\n";
cout<<"x="<<x<<",y="<<y<<endl;
}
void printPoint(){
cout<<"non const type\n";
cout<<"x="<<x<<",y="<<y<<endl;
}
};//main.cpp
#include <iostream>
#include "Point.h"
int main(int argc, const char * argv[])
{
// insert code here...
Point p(10,20);
Point const p1(30,40);
p1.printPoint();
p.printPoint();
//std::cout << "Hello, World!\n";
return 0;
}cout:
Point constructor is called !
Point constructor is called !
const type
x=30,y=40
not const type
x=10,y=20
Point destructor is called !
Point destructor is called !
Program ended with exit code: 0
将类中的
void printPoint()
函数删除时则输出：
Point constructor is called !
Point constructor is called !
const type
x=30,y=40
const type
x=10,y=20
Point destructor is called !
Point destructor is called !
Program ended with exit code: 0
所以类中的非 const成员函数也可调用const类型成员函数。
本文出自 “c0c0s” 博客，请务必保留此出处http://9362125.blog.51cto.com/9352125/1682057
标签：c++
原文地址：http://9362125.blog.51cto.com/9352125/1682057
