Parameter Overloading

The following example shows polymorphism as operator overloading with the „+“-Operator

>>> a = "Spam spam spam"

>>> b = a + "!"

>>> 3 + 4

7

Although we can implement all class behaviour as method functions, it is in many cases more convenient to use operator overloading.

• Python provides specially named methods __x__ to carry out operator overloading, e.g. __add__ for +
• These methods are automatically called if the corresponding operator is found in an expression
• overloaded operators are like built-ins
• most built-in operators can be overwritten

a + b

__add__(self,other)