In Java, if the class has two or more methods having the same name but different in parameters, this process is known as Method Overloading.

The compiler will resolve the call to a correct overloaded method depending on the actual number and/or types of the passed parameters. We can use Method overloading to achieve Java compile-time polymorphism.

The main advantage of method overloading increases the readability of the program.

Java Method Overloading Example

Here is a simple example that illustrates method overloading:

public class Foo {

    public void foozzy(String p, int q) {
        System.out.println("Called foozzy(" + p + ", " + q + ")");
    }

    // different number of arguments
    public void foozzy(String p, int q, int w) {
        System.out.println("Called foozzy(" + p + ", " + q + ", " + w + ")");
    }
    
    // different order of arguments
    public void foozzy(int q, String p) {
        System.out.println("Called foozzy(" + q + ", " + p + ")");
    }
    
    // different types of arguments
    public void foozzy(int p, int q) {
        System.out.println("Called foozzy(" + p + ", " + q + ")");
    }
    
    // not valid - different return type
    /* 
    public boolean foozzy(String p, int q) {
        System.out.println("Called foozzy(" + p + ", " + q + ")");
    }
    */
}

Let's test the above code contains overloaded methods with the main() method:

public class Main {

    public static void main(String[] args) {

        Foo foo = new Foo();
        
        foo.foozzy("text", 1);
        foo.foozzy(1, "text");
        foo.foozzy(-1, 1);
        foo.foozzy("text", -1, 1);
    }
}

Output:

Called foozzy(text, 1)
Called foozzy(1, text)
Called foozzy(-1, 1)
Called foozzy(text, -1, 1)

Read more about method overloading at Method Overloading in Java

Related Java OOPS Examples

• Java Abstraction Example
• Java Inheritance Example
• Java Encapsulation Example
• Java Simple Inheritance Example
• Java Composition Example
• Java Aggregation Example
• Java Delegation Example
• Java Method Overloading Example
• Java Method Overriding Example
• Java Single Inheritance Example
• Java Multilevel Inheritance Example
• Java Hierarchical Inheritance Example
• Java Abstract Class Example
• Java Class Example