A tutorial on constructors in Java; what are they, how to create them, using multiple constructors with different parameters and calling constructors from within other constructors.

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Code for this tutorial:

class Machine {
	private String name;
	private int code;
	
	public Machine() {
		this("Arnie", 0);
		
		System.out.println("Constructor running!");
	}
	
	public Machine(String name) {
		this(name, 0);
		
		System.out.println("Second constructor running");
		// No longer need following line, since we're using the other constructor above.
		//this.name = name;
	}
	
	public Machine(String name, int code) {
		
		System.out.println("Third constructor running");
		this.name = name;
		this.code = code;
	}
}

public class App {
	public static void main(String[] args) {
		Machine machine1 = new Machine();

		Machine machine2 = new Machine("Bertie");
		
		Machine machine3 = new Machine("Chalky", 7);
	}

}

Third constructor running
Constructor running!
Third constructor running
Second constructor running
Third constructor running

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