Question

Public static void main (string args [] ) { int a =1 , b=2; system.out.println (--b - ++a + ++b - --a); system.out.println ("" +a+ ""+b); }

Answer 1

Question :-

int a = 1 , b = 2;

System.out.println(--b - ++a + ++b - --a);

System.out.println(""+a+""+b);

Program Statement :-

import java.util.*;

public class a

{

public static void main (String args[])

{

int a = 1, b = 2;

System.out.println(--b - ++a + ++b - --a);

System.out.println(""+a+""+b);

}

}

Output :-

0

12

Reason :-

--b : This is a prefix decrement. The rule of prefix decrement is to first decrement, then use.

So, the value of b is 2 and after decrement the value of b will be 1.

++a : This is a prefix increment. The rule of prefix increment is to first increment, then use.

So, the value of a is 1 and after increment the value of a will be 2.

++b : This is a prefix increment. The rule of prefix increment is to first increment, then use.

So, the value of b is 1 and after increment the value of b will be 2.

--a : This is a prefix decrement. The rule of prefix decrement is to first decrement, then use.

So, the value of a is 2 and after increment the value of a will be 1.

Mathematically :-

--b - ++a + ++b - --a

1 - 2 + 2 - 1 (Replace the values of a and b)

= 0