Unsigned Right Shift Operator (>>>)

Right shifts the bits of an expression, without maintaining sign.

expression1 >>> expression2

Arguments

• expression1
  Any numeric expression.

• expression2
  Any numeric expression.

Remarks

The >>> operator shifts the bits of expression1 right by the number of bits specified in expression2. Zeroes are filled in from the left. Digits shifted off to the right are discarded. The data type of expression1 determines the data type returned by this operator.

The >>> operator masks expression2 to avoid shifting expression1 by too much. Otherwise, if the shift amount exceeded the number of bits in the data type of expression1, all the original bits would be shifted away to give a trivial result. To ensure that each shift leaves at least one of the original bits, the shift operators use the following formula to calculate the actual shift amount: mask expression2 (using the bitwise AND operator) with one less than the number of bits in expression1.

Example

For example:

var temp
temp = -14 >>> 2

The variable temp has an initial value -14 (11111111 11111111 11111111 11110010 in two's complement binary). When it is shifted right two bits, the value equals 1073741820 (00111111 11111111 11111111 11111100 in binary).

To illustrate how the masking works, consider the following example.

var x : byte = 15;
// A byte stores 8 bits.
// The bits stored in x are 00001111
var y : byte = x >>> 10;
// Actual shift is 10 & (8-1) = 2
// The bits stored in y are 00000011
// The value of y is 3
print(y); // Prints 3

Requirements

Version 1

See Also

Concepts

Operator Precedence

Operator Summary

Coercion By Bitwise Operators

Reference

Unsigned Right Shift Assignment Operator (>>>=)

Bitwise Left Shift Operator (<<)

Bitwise Right Shift Operator (>>)

Change History

Date	History	Reason
August 2009	Modified explanation of first example.	Content bug fix.