• Julian
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    112 years ago

    Ok some of these I understand but what the fuck. Why.

    • @[email protected]
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      62 years ago

      I’m not sure if you really want to know, but:

      greater than, smaller than, will cast the type so it will be 0>0 which is false, ofcourse. 0>=0 is true.

      Now == will first compare types, they are different types so it’s false.

      Also I’m a JavaScript Dev and if I ever see someone I work with use these kind of hacks I’m never working together with them again unless they apologize a lot and wash their dirty typing hands with… acid? :-)

      • @[email protected]
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        12 years ago

        Not a JavaScript dev here, but I work with it. Doesn’t “==” do type coercion, though? Isn’t that why “===” exists?

        As far as I know the operators “>=” and “<=” are implemented as the negation of “<” and “>” respectively. Why: because when you are working with sticky ordered sets, like natural numbers, those operators work.

        Thus “0<=0” -> “!(0>0)” -> “!(false)” -> “true”

        Correct me if my thinking is wrong though.

  • @[email protected]
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    82 years ago

    I know it’s a joke, but it’s an old one and it doesn’t make a lot of sense in this day and age.

    Why are you comparing null to numbers? Shouldn’t you be assuring your values are valid first? Why are you using the “cast everything to the type you see fit and compare” operator?

    Other languages would simply fail. Once more JavaScript greatest sin is not throwing an exception when you ask it to do things that don’t make sense.

    • @[email protected]OP
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      32 years ago

      Shouldn’t you be assuring your values are valid first?

      Step 1: Get to prod

      Step 2-10: Add features

      Step 11: Sell the company before it bites you

  • @[email protected]
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    42 years ago

    I wrote an exam about this stuff yesterday.

    In J’s equality is usually checked in a way that variables are casted to the type of the other one. “25” == 25 evaluates to truey because the string converted to int is equal to the int and the other way around.

    You can however check if the thing is identical, using “25” == 25 which skips type conversion and would evaluate as false.

    I assume the same thing happens here, null is casted to int, which gets the value 0.

  • sheetmulch
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    22 years ago

    I had a fun bug where unit tests started failing on an upgrade. Turns out someone was returning undefined from a comparator. Wtf, people.

  • Björn Tantau
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    12 years ago

    Can someone explain this? I mean, the last result. Usually I can at least understand Javascript’s or PHP’s quirks. But this time I’m stumped.

    • mycus
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      2 years ago

      JS null and undefined shenanigans


      basically:

      1. bigger an lesser comparison types convert null to zero, so is zero bigger than zero? no
      2. == is fucky and to it null only equals undefined and undefined only equals null, so no
      3. is zero bigger than or equal to zero? yeah
    • omnislayer88
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      22 years ago

      My only thought here might be >= is usually the same as !< and maybe thats how it is defined in javascript and since < is false than >= == !false == true