Instance Method

The method of the class is known as an instance method. It is a non-static method defined in the class. Before calling or invoking the instance method, it is necessary to create an object of its class. Let's see an example of an instance method.

$\begin{lstlisting} public class InstanceMethodExample { public static void mai... ..., int b) { s = a+b; //returning the sum return s; } } \end{lstlisting}$

Output:

$\begin{lstlisting} The sum is: 25 \end{lstlisting}$

There are two types of instance method:

Accessor Method
Mutator Method

Accessor Method: The method(s) that reads the instance variable(s) is known as the accessor method. We can easily identify it because the method is prefixed with the word get. It is also known as getters. It returns the value of the private field. It is used to get the value of the private field.

$\begin{lstlisting} public int getId() { return Id; } \end{lstlisting}$

Mutator Method: The method(s) read the instance variable(s) and also modify the values. We can easily identify it because the method is prefixed with the word set. It is also known as setters or modifiers. It does not return anything. It accepts a parameter of the same data type that depends on the field. It is used to set the value of the private field.

$\begin{lstlisting} public void setRoll(int roll) { this.roll = roll; } \end{lstlisting}$

Following is the example of accessor and mutator method.

$\begin{lstlisting} public class Student { private int roll; private String n... ...'+roll); System.out.println(''Student name: ''+name); } } \end{lstlisting}$