What is the difference between the Java operators >> and >>>?

Question

What is the difference between the operator >> and >>>?

Answer 1

>>> right shifts and fills with 0 at the left end, while >> fills with the sign bit.

This makes a difference for the signed integral types (i.e. all but byte), where a negative value has a set sign bit.

Answer 2

>> Signed right shift operator and >>> unsigned right shift operator

Signed Right Shift Operator

The right shift >> operator shifts the left operand to the right side with sign extension by the number of bits specified by its right operand. This means that a value at n place gets shifted to the right causing the n high order bits that contains the same value as that of unshifted value. This operator never throws an exception.

Unsigned Right Shift Operator

The unsigned right shift >>> operator shifts a zero into the leftmost position however the leftmost position after ">>" depends on sign extension.

Answer 3

the signed right shift operator ">>" shifts a bit pattern to the right. The bit pattern is given by the left-hand operand, and the number of positions to shift by the right-hand operand. The unsigned right shift operator ">>>" shifts a zero into the leftmost position, while the leftmost position after ">>" depends on sign extension.

From http://java.sun.com/docs/books/tutorial/java/nutsandbolts/op3.html

Answer 4

Here is an explanation with examples:

http://www.roseindia.net/java/master-java/bitwise-bitshift-operators.shtml

>> fills in the sign the sign bit on the left (i.e. fills in 1 for negative values, 0 for positive), whereas >>> doesn't (always 0). This is convenient when shifting negative values. There is no <<<, since the sign bit is on the left and << thus already behaves like <<< would (filling in zeros, nothing else).