Java Method Overloading

• Method overloading creates many methods (or functions) with same name.
• In other words, one method can do many jobs.
• Method overloading is also called Polymorphism i.e. one method has many forms.
• In method overloading, same name methods are differentiated using two ways:
• 1. Using number of arguments
• 2. Using type of arguments
• When number of arguments in same name methods are same, then methods are differentiated using type of arguments.
• Arguments in method overloading is called signature of the method.

Example

class student {
	int rollno;
	String name;
	void setdata(int rl, String nm)
	{
		rollno = rl;
		name = nm;
	}
	void setdata (int rl)
	{
 		rollno = rl;
		name = "Amit";
	}
	void setdata()
	{
		rollno = 123;
		name = "Umesh";
	}
    void getdata()
	{
		System.out.println("Roll no is " + rollno);
		System.out.println ("Name is " + name);
	}
}

class methodoverloading {
	public static void main (String args[] )
	{ 
           student obj1 = new student();
           obj1.setdata(123,"Amit");
	    obj1.getdata();
	    obj1.setdata (234); 	
	    obj1.getdata();
	    obj1.setdata();
	    obj1.getdata();
	}
}

Explanation of the program

• Class student has two variables rollno and name .
• Class student implements method overloading using setdata () method.
• Three setdata() methods are created. All three methods have different in number of arguments.
• Method setdata(int rl, String nm) has two arguments.
• Method setdata(int rl) has one argument.
• Method setdata() has no argument.
• When the program run, java calls correct setdata() method on basis of arguments.

Output of the program

Roll no is 126
Name is Amit
Roll no is 234
Name is Amit
Roll no is 123
Name is Umesh