this#
this 是指向当前对象的指针,在类的非静态成员函数内部都可以使用。它的典型用途有:
区分同名变量:当成员函数参数与成员变量重名时,用
this->member指代成员变量(见下方setBorn());返回对象自身:链式调用(如
obj.setA().setB())时return *this;在构造函数中调用其他成员函数:明确表示”调用的是这个对象的成员”(见下方带参构造函数)。
注意:this 只在非静态成员函数中有效,静态成员函数没有 this 指针。
#include <cstring>
#include <iostream>
using namespace std;
class Student {
private:
char* name;
int born;
bool male;
public:
Student() {
name = new char[1024]{0};
born = 0;
male = false;
cout << "Constructor: Person()" << endl;
}
Student(const char* name, int born, bool male) {
this->name = new char[1024];
this->setName(name);
this->born = born;
this->male = male;
cout << "Constructor: Person(const char, int , bool)" << endl;
}
~Student() {
cout << "To destroy object: " << name << endl;
delete[] name;
}
void setName(const char* name) { strncpy(this->name, name, 1024); }
void setBorn(int born) { this->born = born; }
// the declarations, the definitions are out of the class
void setGender(bool isMale);
void printInfo();
};
void Student::setGender(bool isMale) {
male = isMale;
}
void Student::printInfo() {
std::cout << "Name: " << name << std::endl;
std::cout << "Born in " << born << std::endl;
std::cout << "Gender: " << (male ? "Male" : "Female") << std::endl;
}
int main() {
Student* class1 = new Student[3]{
{"Tom", 2000, true},
{"Bob", 2001, true},
{"Amy", 2002, false},
};
class1[1].printInfo();
delete[] class1;
return 0;
}