Constructor Declarations in Java Programming

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A constructor method is a method that creates an object.
To create the object, it uses the class as a sort of blueprint for what member variables the object has, what instance methods, and so on.

A class contains constructors that are invoked to create objects from the class blueprint. Constructor declarations
 look like method declarations—except that they use the name of the class and have no return type.
 If you declare a class with no constructors, the compiler will automatically create a default constructor for the class.
 A default constructor takes no parameters (it's a no-arg constructor) and has an empty body. Because the compiler will 
 automatically generate a default constructor if you don't declare any constructors explicitly, all classes are guaranteed
 to have at least one constructor

 class Tea 
{
    // Constructor looks like a method declaration
    // minus the return type
    public Tea() {
        // Body of constructor

The only action taken by the implicit default constructor is to call the superclass constructor using the super() call.
Constructor arguments provide you with a way to provide parameters for the initialization of an object.

The following example consists two constructor one default and one parametrized constructor

The only action taken by the implicit default constructor is to call the superclass constructor using the super() call. Constructor arguments provide you with a way to provide parameters for the initialization of an object.

 public class Figure {

	int length;
	int breadth;
	int height;
	public int getVolume() {
		return (length * breadth * height);
	}
	Figure1() {
		length = 12;
		breadth = 10;
		height = 15;
	}
	Figure1(int l, int b, int h) {
		length = l;
		breadth = b;
		height = h;
	}
	public static void main(String[] args) {
		Figure1 FigureObj1, FigureObj2;
		FigureObj1 = new Figure1();
	    FigureObj2 = new Figure1(10, 20, 30);
        System.out.println("Volume of Figure1 is : " + FigureObj1.getVolume());
		System.out.println("Volume of Figure1 is : " + FigureObj2.getVolume());
	}
}