C++ : Constructors And Destructors 2

Question: 1
C++ program to declare a class named student with attributes as roll, name, and per, further take input for details and display them?
Sol:

#include <iostream>

using namespace std;
class student
{
private:
    int roll;
    char name[20];
    float per;
public:
    student(); //default constructor
    void read();
    void show();

};
//default constructor
student::student()
{
    roll=0;
    name[0]='\0';
    per=0;
}
void student::read()
{
    cout<<"Enter roll,name and per ";
    cin>>roll>>name>>per;
}
void student::show()
{
    cout<<"roll "<<roll<<" name "<<name<<" per "<<per<<endl;
}

int main()
{
    student s1,s2;
    s1.show();
    s2.show();
    return 0;
}

Output:

roll 0 name per 0
roll 0 name per 0

Question:2
C++ program to declare a class named employee with attributes as empno, name and salary, further take input for details and display them?
Sol:

#include <iostream>

using namespace std;
class employee
{
private:
    int empno;
    char name[20];
    float sal;
public:
    employee(); //default constructor
    void read();
    void show();

};
//default constructor
employee::employee()
{
    empno=0;
    name[0]='\0';
    sal=0;
}
void employee::read()
{
    cout<<"Enter empno,name and sal ";
    cin>>empno>>name>>sal;
}
void employee::show()
{
    cout<<"empno "<<empno<<" name "<<name<<" sal "<<sal<<endl;
}

int main()
{
    employee s1,s2;
    s1.show();
    s2.show();
    return 0;
}

Output:

empno 0 name sal 0
empno 0 name sal 0

Question: 3
C++ program to declare a class named bank with attributes as ano, name and bal, further take input for details and display them?
Sol:

#include <iostream>

using namespace std;
class bank
{
private:
    int ano;
    char name[20];
    float bal;
public:
    bank(); //default constructor
    void read();
    void show();

};
//default constructor
bank::bank()
{
    ano=0;
    name[0]='\0';
    bal=0;
}
void bank::read()
{
    cout<<"Enter ano,name and bal ";
    cin>>ano>>name>>bal;
}
void bank::show()
{
    cout<<"ano "<<ano<<" name "<<name<<" bal "<<bal<<endl;
}

int main()
{
    bank s1,s2;
    s1.show();
    s2.show();
    return 0;
}

Output:

ano 0 name bal 0
ano 0 name bal 0