Bitwise OR the right operand with the left operand and assign the result to the left operand.

This is functionally equivalent to the expression:

anOperand1 = anOperand1 | anOperand2;

Performs a bit-by-bit OR of the 32-bit value derived from both operands.

Where a corresponding bit is 1 in either of the two operands, a 1 is inserted into the result. A zero is inserted only when neither operand has a 1 bit at that position.

Although this is classified as an assignment operator it is really a compound of an assignment and a bitwise operator.

The associativity is right to left.

Refer to the Operator Precedence topic for details of execution order.

The new value of anOperand1 is returned as a result of the expression.

The truth table shows the result of this operator for two Boolean primitive values:

This is applied to each corresponding bit pair in the operands.

Warnings:

• The operand to the left of the operator must be an LValue. That is, it should be able to take an assignment and store the value.

Cross-references:

ECMA 262 edition 2 - section - 11.13

ECMA 262 edition 3 - section - 11.13