• marcos@lemmy.world
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      2 years ago
      (+x) % 2 == 0
      

      If you forget for a second it’s Javascript, the language will turn back and bite you.

        • marcos@lemmy.world
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          2 years ago

          This evaluates to NaN for some reason:

          '10' % 0
          

          Since JS doesn’t really differentiate strings from numbers, except on the places it does, it makes sense to make sure you are working with numbers.

        • mindbleach@sh.itjust.works
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          2 years ago

          JS is a language where [1,2,11].sort() returns [1,11,2].

          And if you use a variable instead of a bare array, half the functions are side-effectful, as determined by coin toss.

          And if you try declaring that variable with new Array(3).map() then it will ignore all 3 indices, because undefined is real enough to be enumerated, but not real enough to be iterated, because, and I cannot overstress the importance of this principle in Javascript, go fuck yourself. Go fuck yourself is why.

          • Kindness@lemmy.ml
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            2 years ago

            typeof(null) == ‘object’

            Because some people think planning an entirely new language should take less than 2 weeks. 10 days, in this case.

            See wat for more.

          • PoolloverNathan@programming.dev
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            2 years ago

            Array(3) doesn’t create [undefined, undefined, undefined, ]; it creates [/* hole */, /* hole */, /* hole */, ]. The holes don’t set any property on the array whatsoever, so they are skipped when iterating. How this makes sense, I can’t tell you.