What do these JavaScript bitwise operators do?

• x <<= y (x = x << y)
• x >>= y (x = x >> y)
• x >>>= y (x = x >>> y)
• x &= y (x = x & y)
• x ^= y (x = x ^ y)
• x |= y (x = x | y)

What do these different operators do?

<<, >>

Bit shift left and right, respectively. If you imagine the left operand as a binary sequence of bits, you are shifting those to the left or right by the number of bits indicated by the right operand.

&, ^, |

These are bitwise and, xor, and or, respectively. You can think of & and | as the counterparts to && and ||, except that they will treat their operands as bit vectors, and perform the logical operations on each of the bits. There is no ^^ operator, but this operation is "xor" or "exclusive or". You can think of "a xor b" as "a or b, but not both".

Bitwise Operators