• Fargeol@lemmy.ml
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    7 months ago

    1 - Easiest way to run a script in your browser
    2 - Always finds its way if inputs are bad
    Nan - undefined

      • kevincox@lemmy.ml
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        7 months ago

        To be fair, this is actually reasonable. But it does look stupid on the face of it.

      • joneskind@lemmy.world
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        7 months ago

        When my console throws a NaN I kinda think of it as an Halloween kid receiving a fruit instead of a candy. They won’t say “That’s a fruit”. They’ll say “That’s not a treat”.

        I’m personally pissed more often by a falsy 0.

        Did you know that early analog computers would literally explode when asked to divide by 0?

        Now computers just say “Hey stupid, that shit is not even a Number in a mathematical sense, but sure I’ll add one to it.” instead of “Why would you kill me like this?”

        You can’t really define Infinity as a number, yet it is part of their world.

        So typeof NaN === ‘number’ totally makes sense in that regard.

        If you ever worked with arrays of dates, don’t judge NaN too harshly.

        • Skullgrid@lemmy.world
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          7 months ago

          Falsy zero? What’s wrong with that, 1 is true and 0 is false. I thought that was standard logic?

          • joneskind@lemmy.world
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            7 months ago

            in javascript a property is truthy if it exists

            myThing.property = "some string"
            
            if (myThing.property) { // true
              // do something
            }
            

            It works with everything except of course for falsy values

            myThing.number = someNumberThatShouldNotBeEqualToZero
            
            if (myThing.number) {
              // do something very important with that number that should not be equal to zero
            }
            
            // This can fail at anytime without warning
            

            So you’ve got to be extra careful with that logic when you’re dealing with numbers.

            I am not saying it’s wrong though. I’m saying it’s often annoying.

            • Skullgrid@lemmy.world
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              7 months ago

              ah ok , I think I write this a bit more verbose when using other languages, instead of

              if(thing)
              {
                 stuff;
              }
              
              

              I do

              
              if(thing != null)
              {
                 stuff;
              }
              

              so checking for numbers being truthy & existing didn’t seem like an issue

              • joneskind@lemmy.world
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                7 months ago

                In the case of a non-existing property, the value would be undefined rather than null.

                And while == and != exist in JavaScript, most linters will throw an error and require a === and !== instead as they should be avoided.

                null == undefined // true
                null === undefined // false
                

                Besides, null is a perfectly valid value for a property, just as 0. Working with API Platform, I couldn’t tell the number of times I used this kind of statement:

                if (property || property === null) {
                  // do some stuff
                }
                

                Probably just as much as

                if (property || property === 0) {
                  // do some stuff
                }