4 Adding Methods

 

After reading lesson 4, you will be able to:

  • Understand the components of a method signature
  • Add Getter and Setter methods to your class
  • Add more methods to your program

All programming languages have a way to create a block of reusable code. In Python and other programming languages it is called a function, in Java it is called a method. The idea is that the method performs some action, but the calling program does not need to know exactly how it works, just that it will return the correct result or perform the correct action. 

In Lesson 3, I introduced the topic of encapsulation as a pillar of OO programming.  A key feature of encapsulation is using methods to access the private data of a class. The methods can contain logic to prevent any erroneous data corruption, such as trying to withdraw an amount more than the current balance of a checking account.

Consider This

Have you ever made microwave popcorn? Some microwaves have a button with a label that says ‘popcorn’.  When you place the bag of un-popped popcorn in the microwave and push that button, it starts to heat up the bag until the popcorn kernels get hot enough to pop.  After a certain amount of time, it shuts off and you have a bag of popped popcorn. This is similar to a method in Java.  The microwave has a ‘popcorn’ method.

Can you think of other examples related to common household objects that might be considered an object with one or more methods? 

4.1   Method Signatures

 
 

4.1.1   Visibility Modifier

 
 

4.1.2   Return Type

 

4.1.3   Method Naming Conventions

 

4.1.4   Parameter List

 
 
 

4.1.5   Method Body

 
 

4.2   Adding Getter and Setter Methods

 
 

4.3   Adding More Methods

 
 

4.4   Summary

 
 
 
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