Initialization of composite classes in C ++: Colon syntax (initialization of common data members and reference members)

 

// ================================================ ==============================================

// Name: main. cpp

// Author: ShiGuang

// Version:

// Copyright: sg131971@qq.com

// Description: Hello World in C ++, Ansi-style

// ================================================ ==============================================

 

# Include <iostream>

# Include <string>

 

Using namespace std;

Class Student

{

Int semesHours;

Float gpa;

Public:

Student (int I)

{

Cout <"constructing student. \ n ";

SemesHours = I;

Gpa = 3.5;

}

~ Student ()

{

Cout <"~ Student \ n ";

}

};

 

Class Teacher

{

String name;

Public:

Teacher (string p)

{

Name = p;

Cout <"constructing teacher. \ n ";

}

~ Teacher ()

{

Cout <"~ Teacher \ n ";

}

};

 

Class TutorPair

{

Public:

TutorPair (int I, int j, string p ):

Teacher (p), student (j)

{

Cout <"constructing tutorpair. \ n ";

NoMeetings = I;

}

~ TutorPair ()

{

Cout <"~ TutorPair \ n ";

}

Protected:

Student student;

Teacher teacher;

Int noMeetings;

};

 

Int main (int argc, char ** argv)

{

TutorPair tp (5, 20, "Jane ");

Cout <"back in main. \ n ";

Return 0;

}

Note: The Assignment Method in the program and the call sequence of the constructor destructor.

 

Constructing student.

Constructing teacher.

Constructing tutorpair.

Back in main.

~ TutorPair

~ Teacher

~ Student

In addition, the constructor initializes common data members and reference members.

 

 

// ================================================ ==============================================

// Name: main. cpp

// Author: ShiGuang

// Version:

// Copyright: sg131971@qq.com

// Description: Hello World in C ++, Ansi-style

// ================================================ ==============================================

 

# Include <iostream>

# Include <string>

 

Using namespace std;

 

Class Student

{

Public:

Student (int s, int & k ):

I (s), j (k)

{

} // Values cannot be assigned directly.

Void p ()

{

Cout <I <endl;

Cout <j <endl;

}

Protected:

Const int I;

Int & j;

};

 

Int main (int argc, char ** argv)

{

Int c = 123;

Student s (9818, c );

S. p ();

 

Return 0;

}

 

9818

123

 

From Study Notes of sg131971