Calling Methods…

Example : BoxDemo

import java.io.*;
class Box
{
	double width;
	double height;
	double depth;
	

}
class BoxDemo{
public static void main(String args[])
{
Box mybox=new Box();
double vol;
mybox.width=10;
mybox.height=20;
mybox.depth=15;
vol=mybox.width*mybox.height*mybox.depth;
System.out.println("volume is "+vol);
}
}

Overloading methods…

Example : OverloadDemo

import java.io.*;
class OverloadDemo
{
void multi()
{
System.out.println("No value to multiply");
}
void multi(int a)
{
System.out.println("a*a:"+a*a);
}
void multi(int a,int b)
{
System.out.println(a+"and "+b+":"+a*b);
}
double multi(double a)
{
return a*a;
}
public static void main(String args[])
{
OverloadDemo ob=new OverloadDemo();
double result;
ob.multi();
ob.multi(10);
ob.multi(10,20);
result=ob.multi(123.25);
System.out.println("Result of ob.multi(123.25):"+result);
}
}

Argument passing in java…

Call-by-Value…

import java.io.*;
class CallTest
{
void change(int i)
{
i=i+1;
System.out.println("Inside function i="+i);
}
}
class callbyvalue
{
public static void main(String[] args)
{
CallTest ob=new CallTest();
int a=10;
System.out.println("Before call a="+a);
ob.change(a);
System.out.println("After call a="+a);
}
}

Call-by-Reference…

import java.io.*;
class RefTest
{
int a,b;
void change(RefTest o)
{
o.a+=2;
o.b-=2;
}
void show()
{
System.out.println("A="+a+",B="+b);
}
}
class CallByRef
{
public static void main(String args[])
{
RefTest ob1=new RefTest();
RefTest ob2=new RefTest();
ob2.a=10;
ob2.b=20; 
System.out.println("Before calling change");
ob2.show();
ob1.change(ob2);
System.out.println("After calling change");
ob2.show();
}
}