Bitshift Operators

Bitshift operators << and >> move bits within an integer. The bits are shifted by an number of position, to the right or to the left. They are equivalent to multiplying or dividing by a power of 2.

<?php

$a = 3;       // binary : 11
echo $a >> 1; // binary : 1 (the last 1 is lost)
echo $a << 2; // binary : 1100

?>

Documentation

See also Are Bitwise Operators Still Relevant in Modern PHP?

Related : Logical operators, Bitwise Operators