Selenium WebDriver Java Tutorials - Object In Java

What Is An Object In Java?

If Interviewer ask you this question then your answer should be like this : Object Is an Instance of class. In other words we can say object Is bundle of related methods and variables. Every object has Its own states and behavior. Objects are generally used with constructors In java software development language. Understanding of object Is very Important for Selenium WebDriver software testing tool learner because we have to create and use objects In our test case development of software web applications. We can create multiple objects for the same class having Its own property in java software development language.

Let us take one real world scenario to understand object clearly. Simplest example Is bicycle Is an object of vehicle class having Its own states and behavior. Same way, motorcycle Is another object of vehicle class. Few properties for both the objects are same like wheels=2, handle=1. Few properties for both the objects are different like price, color, speed etc..

How to create object?
You can create object of class vehicle using new keyword as bellow.

public class vehicle { 
 public static void main(String[] args) {
  //Created object for vehicle class using new keyword.
  //bicycle is the reference variable of this object.
  vehicle bicycle = new vehicle("Black");
  
 } 
 //Constructor with color parameter passed. It will retrieve value from object vehicle. 
 public vehicle(String color){
  //Retrieved value will be printed.
  System.out.println("Color Of vehicle Is "+color);  
 } 
}

Console Output will looks like bellow when you will run above example.

Color Of vehicle Is Black

In above example, Used one constructor to pass the value of object. We will look about constructor In my upcoming post. Please remember here one thing - bicycle Is not an object. It Is reference variable of object vehicle. Based on this example, Now we can say that object has three parts as bellow.

• Declaration : Variable declaration for object. In this example, bicycle is the reference variable for object.
• Instantiation : Object creation using new keyword Is called as Instantiation.
• Initialization : Call to a constructor Is known as object initialization.

As described In PREVIOUS POST, You can use object of class to access non static variables or methods of class in different class too. This way you can use object of class and also you can create multiple objects of any class in java software development language.

Bellow given example will show you how to create multiple object of class to pass different kind of multiple values In constructor.

public class vehicle { 
 
 public static void main(String[] args) {
                //Create 2 objects of class. Both have different reference variables.
  vehicle bicycle = new vehicle("black", 2, 4500, 3.7);
  vehicle motorcycle = new vehicle("Blue", 2, 67000, 74.6);

 }
 
 public vehicle(String color, int wheels, int price, double speed){
  System.out.println("Color = "+color+", Wheels = "+wheels+", Price = "+price+", Speed = "+speed);
 } 
}

Output of above program will looks like bellow.

Color = black, Wheels = 2, Price = 4500, Speed = 3.7
Color = Blue, Wheels = 2, Price = 67000, Speed = 74.6

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