Instance Methods in Java

An instance method belongs to an object of a class and requires an instance to be called. It can access and modify the object’s instance variables and can also call other instance or static methods.

• Can access and modify instance variables (object state).
• Can accept parameters and return a value.
• Can call other instance methods or static methods.
• Supports encapsulation and object-oriented design.
• Follows the divide-and-conquer principle in larger applications.

Hello, Alice!

Explanation:

• greet() is an instance method.
• It prints the name of the object.
• Called using an object p of the Person class.

Syntax

modifier return_type method_name( )
{
method body ;
}

• modifier: It defines the access type of the method, and it is optional to use.
• return_type:Type of value returned by the method (int, void, String, etc.).
• method_name: Name of the method.
• method body: The method body describes what the method does with statements.

Example: Instance Method With Parameter

Sum : 5
GFG!

Explanation:

• GFG class has an instance method add() that accepts two integers.
• The method adds the numbers and prints their sum.
• We create an object and call add() with parameters 2 and 3.

Types of Instance Methods:

There are two types of Instance methods in Java:

1. Accessor Methods (Getters)

Getter methods are used to retrieve the value of a private instance variable. They provide controlled access to object data without allowing modification.

Balance: 100

Explanation:

• Returns the value of a private instance variable.
• Provides controlled access to the data.

2. Mutator Methods (Setters)

Setter methods are used to modify or update the value of a private instance variable. They allow controlled updates while maintaining encapsulation.

Balance: 150

Explanation:

• Modifies the value of a private instance variable.
• Works together with a getter to control access to data.