JavaScript tutorial:
|= Operator

The (|=) operator is use to perform a bitwise OR on an expression.

Syntax

result |= expression

The |= operator syntax has these parts:

Part	Description
result	Any variable.
expression	Any expression.

Example

Using this operator is exactly the same as specifying:

result = result | expression

The |= operator looks at the binary representation of the values of result and expression and does a bitwise OR operation on them. The result of this operation behaves like this:

0101 (result)
1100 (expression)
----
1101 (output)

Any time either of the expressions has a 1 in a digit, the result has a 1 in that digit. Otherwise, the result has a 0 in that digit.

For information on when a run-time error is generated by the |= operator, see the Operator Behavior table.

See also: | Operator, Operator Behavior, Operator Precedence, Operator Summary