oop Polymorphism Method Overloading

Example

Method overloading is the way of using polymorphism inside a class. We can have two or more methods inside the same class, with different input parameters.

Difference of input parameters can be either:

• Number of parameters
• Type of parameters (Data type)
• Order of the parameters

Let's take a look at them separately (These examples in java, as I am more familiar with it - Sorry about that):

1. Number of Parameters

    public class Mathematics { 
        public int add (int a, int b) {
            return (a + b);
        }
   
        public int add (int a, int b, int c) {
            return (a + b + c); 
        }
   
        public int add (int a, int b, int c, int c) {
            return (a + b + c + d);
        }
    }
   

   Look carefully, you can see the method's return type is the same - int, but theree of these methods having different number of inputs. This is called as method over loading with different number of parameters.

   PS: This is a just an example, there's no need to define add functions like this.

2. Type of parameters

   public class Mathematics { 
       public void display (int a) {
           System.out.println("" + a);
       }
   
       public void display (double a) {
           System.out.println("" + a);
       }
   
       public void display (float a) {
           System.out.println("" + a);
       }
   }
   

   Note that every method has the same name and same return type, while they have different input data types.

   PS: This example is only for explaining purpose only.

3. Order of the parameters

   public class Mathematics {
       public void display (int a, double b) {
           System.out.println("Numbers are " + a + " and " + b);
       }
   
       public void display (double a, int b) {
           System.out.println("Numbers are " + a + " and " + b);
       }
   }
   

   PS: This example is also for explaining purpose only.