Accessor Methods

Accessor Methods

Concept of Accessor Methods

• Accessor methods enable other objects to retrieve values of instance variables in a secure way.
• They are also known as getters because they get the attribute values.

Reason to Use Accessor Methods

• Accessor methods promote encapsulation, one of the major principles of Object Oriented Programming (OOP).
• They hide the internal details of a class, providing a way to limit the access to the internal data.

Basic Structure of Accessor Methods

• The method name often starts with ‘get’ followed by the variable name.
• It typically is a public method and returns the value of the private attribute, enabling controlled access.

Accessor Method in Action

• Consider a class named ‘Rectangle’ with a private attribute ‘length’.
• An accessor method to get the ‘length’ will be written as:

  public class Rectangle {
    private double length;
  
    public double getLength() {
        return length;
    }
  }
  

• The above accessor method ‘getLength’ retrieves the value of ‘length’ attribute.

Role in Application Building

• Accessor methods are crucial in building real-world applications where certain attributes or properties need to be kept private.
• They allow developers to maintain strict control over how and when data can be accessed.

Java Specifics

• In Java, it’s standard practice to declare instance variables as private and provide accessor methods for them.

Best Practices

• Avoid any side effects in accessor methods.
• Preferably, they should only return the value of the attribute, without altering any state.