C++筆記之析構(gòu)函數(shù)

2019-11-14 12:48:04

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供稿：網(wǎng)友

析構(gòu)函數(shù)是在對(duì)象銷(xiāo)毀時(shí)被調(diào)用的函數(shù)，當(dāng)實(shí)例化一個(gè)對(duì)象時(shí)占用的資源需要程序員手動(dòng)回收時(shí)，一般用來(lái)釋放資源。析構(gòu)函數(shù)的定義格式：~類(lèi)名(){}。析構(gòu)函數(shù)沒(méi)有任何參數(shù)。

//文件名為Student.h#include <iostream>#include <string>using namespace std;class Student {public: Student(); Student(const Student &stu); ~Student();//析構(gòu)函數(shù),對(duì)象被銷(xiāo)毀時(shí)會(huì)自動(dòng)調(diào)用PRivate: char *m_pName;};#include "Student.h"Student::Student() { m_pName = new char[20];//從堆中申請(qǐng)的內(nèi)存，需要手動(dòng)回收}Student::Student(const Student &stu) { cout << "調(diào)用拷貝構(gòu)造函數(shù)" << endl;}Student::~Student() { delete m_pName;//釋放對(duì)象占用的內(nèi)存 m_pName = NULL; cout << "我要死啦！" << endl;//函數(shù)體}/*作為函數(shù)參數(shù)傳遞過(guò)來(lái)的對(duì)象實(shí)際上生成了一個(gè)對(duì)象的副本（利用拷貝構(gòu)造函數(shù)），當(dāng)函數(shù)執(zhí)行完畢后，這個(gè)對(duì)象的副本會(huì)被銷(xiāo)毀，這時(shí)也會(huì)調(diào)用析構(gòu)函數(shù)*/void test(Student stu) {}int main() { Student stu1; Student stu2 = stu1; Student stu3(stu1); test(stu1); system("pause"); return 0; //這里并沒(méi)有調(diào)用析構(gòu)函數(shù)，但是程序執(zhí)行完畢時(shí)系統(tǒng)會(huì)自動(dòng)調(diào)用}