Constructors in Java
Java constructors or constructors in Java is a terminology been used to construct something in our programs. A constructor in Java is a special method that is used to initialize objects. The constructor is called when an object of a class is created. It can be used to set initial values for object attributes.
In Java, a constructor is a block of codes similar to the method. It is called when an instance of the class is created. At the time of calling the constructor, memory for the object is allocated in the memory. It is a special type of method which is used to initialize the object. Every time an object is created using the new() keyword, at least one constructor is called.
How Constructors are Different From Methods in Java? Constructors must have the same name as the class within which it is defined while it is not necessary for the method in Java.Constructors do not return any type while method(s) have the return type or void if does not return any value.Constructors are called only once at the time of Object creation while method(s) can be called any number of times.
Now let us come up with the syntax for the constructor being invoked at the time of object or instance creation.
Need of Constructor
Think of a Box. If we talk about a box class then it will have some class variables (say length, breadth, and height). But when it comes to creating its object(i.e Box will now exist in the computer’s memory), then can a box be there with no value defined for its dimensions. The answer is no.
So constructors are used to assigning values to the class variables at the time of object creation, either explicitly done by the programmer or by Java itself (default constructor).
