AssignmentExpression :
ConditionalExpression
LeftHandSideExpression AssignmentOperator AssignmentExpression
AssignmentExpressionNoIn :
ConditionalExpressionNoIn
LeftHandSideExpression AssignmentOperator AssignmentExpressionNoIn
AssignmentOperator : one of
= *= /= %= += -= <<= >>= >>>= &= ^= |=
The NoIn versions behave identical.
The assignment operator simply executes the algorithm in 11.13.1. The other operators use the algorithm in 11.13.2.