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javascriptbit-shift

JavaScript bit-shifting

I would like to shift this unsigned number: 1479636484000 7 bits to the right. Is this possible in JavaScript?

Both

1479636484000 >> 7

and

1479636484000 >>> 7

returns an incorrect answer (for me). The correct answer should be 11559660031. I guess there's some sign bit involved here, and maybe the number is too large to be supported. But is there any clever way of getting around it?

Solution

  • Bitwise operations in JavaScript start by truncating the number to a 32-bit integer. Your numbers are too big. The "clever way" to get around that limitation is to implement your own numeric library.

    Note that floating-point division by 128 gets you the right answer (if you drop the fraction).