Tag: constructor

In this Java video tutorial we have covered both ways of adding numbers: using constructors as well as using methods.

Constructors:

Constructor name and the class name must be same.
No return type.
There are 3 types of constructors:
1. Default constructors.
2. Parameterized constructors.
3. Copy Constructors.

In this video tutorials we have shown the use of Parameterized constructors.

calc(int a, int b)
{
no1 = a;  
no2 = b;  
}

Adding and displaying the result:

public void sum()
{
System.out.println("Sum of "+no1+" and "+no2+" is "+(no1+no2));
}

Strings are written inside double quotes and the variables written outside the double quotes will display the value stored in them.
+ (plus) is concatenation operation.
(no1+no2) adds the value present in no1 and no2 and displays the result of addition.

Video Tutorial

Object Creation:

/* calc c; // object declaration. It will have null in it.
   c = new calc(20,10); // Construction call
*/ 
   calc c = new calc(30, 10);

Full Java code: Using Constructors & Member Function to add two numbers(add.java)

import java.lang.*;
 
class calc
{
int no1, no2;
 
calc(int a, int b)
{
no1 = a;  // 30
no2 = b;  // 10
}
 
/*
public void assign(int a, int b)
{
no1 = a;  // 30
                no2 = b;  // 10
}
*/ 
public void sum()
{
System.out.println("Sum of "+no1+" and "+no2+" is "+(no1+no2));
}
}
 
class add
{
public static void main(String args[])
{
/* calc c; // object declaration. It will have null in it.
c = new calc(20,10); // Construction call
*/ 
calc c = new calc(30, 10);
//c.assign(30,10);
c.sum();
}
}

Member functions are called with the help of object.
Syntax:
object.memberfuntion();