Question

For the following code lines:

public class Base{

    private int num1 = 0;
    private int num2 = 0;
    private static int dif = 0;

    public Base(int num){
         this(num,num+1);
         System.out.println("Base constructor1");
    }

    public Base(int num1, int num2){
         System.out.println("Base constructor2");
         this.num1 = num1;
         this.num2 = num2;
         dif = num2 - num1;
    }

    public int sum(){
        return num1 + num2;
    }

    public static int getDif(){
        return dif;
    }
}

What should those 2 lines print ?

Base b1 = new Base(10);
Base b2 = new Base(4,7);

I think that if I’ll understand the following line: this(num,num+1); I will understand everything…

thnx

Answer 1

this(num,num+1);

calls following constructor in same object

public Base(int num1, int num2){

Why?

If user created an object for Base by calling constructor with single param, your code does some default calculations in above constructor and sets num2 and diff values.