Q1: What will be the output of the program?

public class Test 
{ 
    public static void leftshift(int i, int j) 
    {
        i <<= j; 
    } 
    public static void main(String args[]) 
    {
        int i = 4, j = 2; 
        leftshift(i, j); 
        System.out.println(i); 
    } 
}

ANS:A - 2

Java only ever passes arguments to a method by value (i.e. a copy of the variable) and never by reference. Therefore the value of the variable i remains unchanged in the main method. If you are clever you will spot that 16 is 4 multiplied by 2 twice, (4 * 2 * 2) = 16. If you had 16 left shifted by three bits then 16 * 2 * 2 * 2 = 128. If you had 128 right shifted by 2 bits then 128 / 2 / 2 = 32. Keeping these points in mind, you don't have to go converting to binary to do the left and right bit shifts.