Difference between Over loading and Overriding

 

METHOD OVERLOADING	METHOD OVERRIDING
It occurs within the class.	It is performed in two classes with inheritance relationships.
Method overloading may or may not require inheritance.	Method overriding always needs inheritance.
In method overloading, methods must have the same name and different signatures.	In method overriding, methods must have the same name and same signature.
Poor Performance due to compile time polymorphism.	It gives better performance. The reason behind this is that the binding of overridden methods is being done at runtime.
The argument list should be different while doing method overloading.	The argument list should be the same in method overriding.
The overloaded and overloading methods must be in the same class	The overriding method must take the same number and type of parameters as the overridden method – otherwise, you would just be overloading the method.

Method overloading is defining several methods in the same class, that accept different numbers and types of parameters	Method overriding is when a child class redefines the same method as a parent class, with the same parameters.
Method overloading is a compile-time polymorphism.	Method overriding is a run-time polymorphism.
Method overloading is used to increase the readability of the program.	Method overriding is used to provide the specific implementation of the method that is already provided by its super class
The return type can be freely modified.	The return type must not change
Static method binding	Dynamic method binding
Exceptions can change	Exception can be reduced or eliminated
Overloading lets you define a similar operation in different ways for different data	Overriding lets you define a similar operation in different ways for different object types
EXAMPLE- // Java program to demonstrate working of method // overloading in Java    publicclassSum {     publicintsum(intx, inty) { return(x + y); }    publicintsum(intx, inty, intz)     {         return(x + y + z);     }     publicdoublesum(doublex, doubley)     {         return(x + y);     } publicstaticvoidmain(Stringar[])     {         Sum s = newSum(); System.out.println(s.sum(10, 20));         System.out.println(s.sum(10, 20, 30));         System.out.println(s.sum(10.5, 20.5));     } }	EXAMPLE- // A Simple Java program to demonstrate // method overriding in java   classParent {     voidshow() { System.out.println("Parent's show()"); } }   classChild extendsParent {     voidshow()     { System.out.println("Child's show()");     } }  classMain {     publicstaticvoidmain(String[] args)     {   Parent obj1 = newParent();         obj1.show(); Parent obj2 = newChild();         obj2.show();     } }