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php Right Shift Operator

Form

Semantics

>> (>>: integer × integer → integer)

name: Right Shift
operand types: integer
result type: integer
result value: The bits of the left operand are shifted right by the number of positions of the right operand.  The bit positions vacated on the left are filled with the sign bit, and bits shifted out on the right are discarded.
side effect: None.
associativity: Left to right.

Remarks

• Left and right operands are implicitly cast to integer before the operation is applied if necessary.
• On Intel IA32 processors, only the right 5 bits of the right operand are used.  This means that the effective right operand will always be in the range of 0 to 31.
• The sign of the result wlll be the same as the sign of the left operand.

Example

<?php
  RightShift (4, 2);
  RightShift (-1, 5);
  RightShift (-1, -5);
  RightShift (2147483647, 32);
  RightShift (2147483647, 1);
  RightShift (0x80000001, 1);

function RightShift ($A, $B) {
  echo  "$A >> $B = ", ($A >> $B), "\n";
}
?>

Output

4 >> 2 = 1
-1 >> 5 = -1
-1 >> -5 = -1
2147483647 >> 32 = 2147483647
2147483647 >> 1 = 1073741823
2147483649 >> 1 = -1073741824

See Also

php Right Shift Expression  <rightshift-expression>  php Left Shift Operator  <leftshift-operator>

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copyright 2005-2006, j.h.young, revised 2/9/06

php Right Shift Expression / php Left Shift Operator /