Instance Variables in Java

The data components of a class are often referred to as the instance variables of that class. Also, class object attributes are often called fields to help distinguish them from other variables you might use.

This is the source class for ‘myObject’. In line 3 we have declared a instance variable (known as a class field, because it declares inside class block, not in a method). ‘setText’ method will set a value to strText, and ‘getText’ method will return the value in strText.
Save this class as “InstanceVariables.java”

public class InstanceVariables
{
String strText;

public void setText()
{
strText = "This is VariableUserMethod";
}

public string getText()
{
return strText
}
}


This is the class which uses “InstanceVariables.java” through the object “myObject”.

public class TextEdit
{
public static void main(String[] args)
{
InstanceVariables myObject = new InstanceVariables();
//without arguments
InstanceVariables myArgObject = new InstanceVariables("With Arguments");

System.out.println("Getting the value with myObject");
System.out.println("Value is:" + myObject.getText());

System.out.println("Getting the value with myNewObject");
System.out.println("Value is:" + myArgObject.getText());
}
}



This is the output:

Tip: An object is constructed by instantiating a class. The process of creating an object of a class is called as instantiation and the created object is called as an instance.