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I have a question. I'm trying to sum up ints in node, but this happens in the repl:

144115291155089440
> 32 + 2048 + 16384 + 34359738368 + 68719476736 + 144115188075855870 + 4
144115291155089440
> 32 + 2048 + 16384 + 34359738368 + 68719476736 + 144115188075855870
144115291155089440

Can someone explain why this is happening? Context is I'm referring to this API (https://moz.com/help/guides/moz-api/mozscape/api-reference/url-metrics) and trying to use return a Cols value for their BitFlag.

Thanks again!

Felix Kling
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Brian Zhou
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  • have you checked what your max int is? It sound like you are exceeding the max int value and need to use another data type. This is a good reason to learn c or c++ programming because you learn that you have to check that operations don't exceed max int values. – Matthew Lagerwey Feb 19 '18 at 21:59
  • `Number.MAX_SAFE_INTEGER => 9007199254740991` – Felix Kling Feb 19 '18 at 22:01
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    See also [max integer value in JavaScript](https://stackoverflow.com/q/21350175/218196) – Felix Kling Feb 19 '18 at 22:01
  • @MatthewLagerwey unfortunately you must write a software implementation in JavaScript to handle integers over `2**53-1`, since there are no native data types for `Uint64` or `Int64`. – Patrick Roberts Feb 19 '18 at 22:08
  • [Here's one I wrote a while back](https://github.com/patrickroberts/complex-js/blob/master/src/long.js). It handles up to `2**64-1`, but I haven't written a `toString()` method for it since I didn't need one. I'll leave that up to you. – Patrick Roberts Feb 19 '18 at 22:11

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