• @joneskind@lemmy.world
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      2 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.

        • @joneskind@lemmy.world
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          12 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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            12 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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              2 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
              }