Method overloading


method overloading
Several ways to call a method (method overloading)
In Python you can define a method in such a way that there are multiple ways to call it.

Given a single method or function, we can specify the number of parameters ourself.

Depending on the function definition, it can be called with zero, one, two or more parameters.

This is known as method overloading. Not all programming languages support method overloading, but Python does.

Related course
Complete Python Bootcamp: Go from zero to hero in Python

Method overloading example

We create a class with one method sayHello(). The first parameter of this method is set to None, this gives us the option to call it with or without a parameter.

An object is created based on the class, and we call its method using zero and one parameter.

#!/usr/bin/env python
 
class Human:
 
    def sayHello(self, name=None):
 
        if name is not None:
            print 'Hello ' + name
        else:
            print 'Hello '
 
# Create instance
obj = Human()
 
# Call the method
obj.sayHello()
 
# Call the method with a parameter
obj.sayHello('Guido')

Output:

Hello 
Hello Guido

To clarify method overloading, we can now call the method sayHello() in two ways:

obj.sayHello()
obj.sayHello('Guido')

We created a method that can be called with fewer arguments than it is defined to allow.

We are not limited to two variables, your method could have more variables which are optional.


Encapsulation
Inheritance

16 thoughts on “Method overloading

  1. Radek Duda - June 9, 2017

    Just short notice about boolean condition. It could be shortened from the form:

    if name is not None:

    to

    if name: