作用
C++提供了初始化列表语法，用来初始化属性
语法
构造函数(参数): 属性1(值1),属性2(值2)...{函数体}
示例：
传统初始化操作
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| #include<iostream>
using namespace std;
class Person{
public:
Person(int a, int b, int c) {
m_A = a;
m_B = b;
m_C = c;
}
int m_A;
int m_B;
int m_C;
};
int main() {
Person p(10, 20, 30);
cout << "m_A=" << p.m_A << endl << "m_B=" << p.m_B << endl<< "m_C=" << p.m_C << endl;
return 0;
}
|
初始化列表方式初始化
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| #include<iostream>
using namespace std;
class Person{
public:
Person() :m_A(10),m_B(20),m_C(30) {
}
int m_A;
int m_B;
int m_C;
};
int main() {
Person p;
cout << "m_A=" << p.m_A << endl << "m_B=" << p.m_B << endl<< "m_C=" << p.m_C << endl;
return 0;
}
|
上列代码中m_A、B、C的值已经无法更改，为了让这些值更灵活的传入
可以这样写
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| #include<iostream>
using namespace std;
class Person{
public:
Person(int a, int b, int c) :m_A(a),m_B(b),m_C(c) {
}
int m_A;
int m_B;
int m_C;
};
int main() {
Person p(20,30,10);
cout << "m_A=" << p.m_A << endl << "m_B=" << p.m_B << endl<< "m_C=" << p.m_C << endl;
return 0;
}
|
