Microsoft® JScript
Compound Assignment Operators
Language Reference
Addition (+=)
Bitwise AND (&=)
Bitwise OR (|=)
Bitwise XOr (^=)
Division (/=)
Left Shift (<<=)
Modulus (%=)
Multiplication (*=)
Right Shift (>>=)
Subtraction (-=)
Unsigned Right Shift (>>>=)