Why use constructor in java program

Employee is a default constructor of Employee class in this code. And when you do not explicitly define a constructor for a class, then Java creates a default constructor for the class. If you see the codes written in previous examples you will not find any constructors defined there, despite we were able to create object of those classes, this is because only for that reason.

Here in this example, object employee1 and employee3 is initialized with default constructor Employee of Employee class. Here we have created the default constructor Employee for Employee class and we are initializing the objects with some user defined values. Geek String name, int age. Geek long id. Output Constructor with one argument - String : Shikhar Constructor with two arguments : String and Integer : Dharmesh 26 Constructor with one argument : Long : Attention reader!

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Start Your Coding Journey Now! Unlike Java methods , a constructor has the same name as that of the class and does not have any return type. For example,. Here, Test is a constructor. It has the same name as that of the class and doesn't have a return type. Recommended Reading: Why do constructors not return values. In the above example, we have created a constructor named Main. Inside the constructor, we are initializing the value of the name variable.

Here, when the object is created, the Main constructor is called. And, the value of the name variable is initialized. If a constructor does not accept any parameters, it is known as a no-argument constructor. In the above example, we have created a constructor Main. Here, the constructor does not accept any parameters. Hence, it is known as a no-arg constructor. Once a constructor is declared private , it cannot be accessed from outside the class.

So, creating objects from outside the class is prohibited using the private constructor. Here, we are creating the object inside the same class. Hence, the program is able to access the constructor. To learn more, visit Java Implement Private Constructor. However, if we want to create objects outside the class, then we need to declare the constructor as public.

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