In depth analysis of constructors and destructors in C++

Constructor:
This is done automatically when a class instantiates an object, initializing the data in the class. Constructors can be from load, there can be more than one, but only one default constructor.

Destructor:
A function that does something before revoking the memory held by an object. Destructors cannot be overridden, there can only be one.

The sequence of constructor and destructor calls:
Post-destructor constructed first and post-conformation folded first. It's like a stack, first in, then out.

#include<iostream>
#include<string>
using namespace std;
class Student{
 public:
  Student(string,string,string);
  ~Student();
  void show();
 private:
  string num;
  string name;
  string sex;
};
Student::Student(string nu,string na,string s){
 num=nu;
 name=na;
 sex=s;
 cout<<name<<" is builded!"<<endl;
}
void Student::show(){
 cout<<num<<"t"<<name<<"t"<<sex<<endl;
}
Student::~Student(){
 cout<<name<<" is destoried!"<<endl;
}
int main(){
 Student s1("001"," thousand "," male ");
 s1.show();
 Student s2("007"," Steel hand "," female ");
 s2.show();
 cout<<"nihao"<<endl;
 cout<<endl;
 cout<<"NIHAO"<<endl;
 return 0;
}

< img Alt = "" border = 0 SRC =" / / files.jb51.net/file_images/article/201309/20130903080000.png ">

A thousand hands constructed first and a thousand hands resulting in subsequent destruction; After the construction of the class hand, the result of the first folded class hand.

Features:
The destructor is called only when the main function ends or the exit function ends the program.

If the object is defined in a function, its constructor is called when the object is created, and the destructor is called first when the function call ends and the object is released.

#include<iostream>
#include<string>
using namespace std;
class Student{
 public:
  Student(string,string);
  ~Student();
  void show();
  string num;
  string name;
};
Student::Student(string nu,string na){
 num=nu;
 name=na;
 cout<<name<<" is builded!"<<endl<<endl;
}
void Student::show(){
 cout<<num<<"t"<<name<<endl<<endl;
}
Student::~Student(){
 cout<<name<<" is destoried!"<<endl<<endl;
}
void fun(){
 cout<<"============ call fun function ============"<<endl<<endl; 
 Student s2("002"," Automatic local variable ");//Define an automatic local object
 s2.show();
 static Student s3("003"," Static local variable ");//Define static local variables
 s3.show();
 cout<<"===========fun End of function call =============="<<endl<<endl;
}
int main(){
 Student s1("001"," The global variable ");
 s1.show();
 fun();
 cout<<"nthis is some content before the endn";//This is a section before the main function ends and after the function is called
 cout<<endl;
 return 0;
}

< img Alt = "" border = 0 SRC =" / / files.jb51.net/file_images/article/201309/20130903080209.png ">