Bitwise right shift operators in Java

In C/C++ there is only one right shift operator ‘>>’ which should be used only for positive integers or unsigned integers. Use of right shift operator for negative numbers is not recommended in C/C++, and when used for negative numbers, output is compiler dependent (See this). Unlike C++, Java supports following two right shift operators.

1) >> (Signed right shift) In Java, the operator ‘>>’ is signed right shift operator. All integers are signed in Java, and it is fine to use >> for negative numbers. The operator ‘>>’ uses the sign bit (left most bit) to fill the trailing positions after shift. If the number is negative, then 1 is used as a filler and if the number is positive, then 0 is used as a filler. For example, if binary representation of number is 10….100, then right shifting it by 2 using >> will make it 11…….1.
See following Java programs as example ‘>>’

filter_none

edit
close

play_arrow

link
brightness_4
code

class Test {
    public static void main(String args[])  {
       int x = -4;
       System.out.println(x>>1);   
       int y = 4;
       System.out.println(y>>1);   
    }    
}

chevron_right


Output:

-2
2

2) >>> (Unsigned right shift) In Java, the operator ‘>>>’ is unsigned right shift operator. It always fills 0 irrespective of the sign of the number.

filter_none

edit
close

play_arrow

link
brightness_4
code

class Test {
    public static void main(String args[])  {
  
       // x is stored using 32 bit 2's complement form. 
       // Binary representation of -1 is all 1s (111..1)       
       int x = -1;  
  
       System.out.println(x>>>29);  // The value of 'x>>>29' is 00...0111
       System.out.println(x>>>30);  // The value of 'x>>>30' is 00...0011 
       System.out.println(x>>>31);  // The value of 'x>>>31' is 00...0001 
   }    

chevron_right


Output:

7
3
1

Please write comments if you find anything incorrect, or you want to share more information about the topic discussed above.

Don’t stop now and take your learning to the next level. Learn all the important concepts of Data Structures and Algorithms with the help of the most trusted course: DSA Self Paced. Become industry ready at a student-friendly price.




My Personal Notes arrow_drop_up

Improved By : nagen010