Comment on I'll just sort it myself

LanternEverywhere@kbin.social ⁨9⁩ ⁨months⁩ ago

• ImpossibleRubiksCube@programming.dev ⁨9⁩ ⁨months⁩ ago

  JavaScript is what’s called an “untyped” language, so here, it assumes that the numbers are words, and tries to sort them alphabetically. Specifically, it tries to sort them alphabetically as a dictionary would in a left-to-right language like English. In this case, just as “apple” would come before “asterisk”, 100000 would come before 21.

  (Some would argue that it’s more of a “weakly typed” language, I know, but I’m trying not to be pedantic here.)

  Sorting them as actual numbers would require some extra explicit instructions and guides. Most typed languages, like C, aren’t like this.

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  • affiliate@lemmy.world ⁨9⁩ ⁨months⁩ ago

    is there a good reason for javascript to work like that? python also isn’t typed like C and it sorts integer lists in the “normal” way, so it seems avoidable. (i don’t really know what im talking about here. i’ve never used javascript and i’m not familiar with how typing works under the hood.)

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    • Quasari@programming.dev ⁨9⁩ ⁨months⁩ ago

      Mainly because JavaScript was designed to work along side HTTP in a browser. Most of its input will be text, so defaulting common behavior to strings makes some sense.

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      • severien@lemmy.world ⁨9⁩ ⁨months⁩ ago

        That’s misleading at best and most likely just false, and it’s worrying it’s so upvoted.

        There’s no historical record explaining why this was designed this way, but we can infer some things. HTTP is very unlikely factor, XHR / AJAX has been added years after the .sort() function.

        The trouble with JS arrays is that they can contain any values - e.g. [false, undefined, 1567, 10, “Hello world”, { x: 1 }]. How do you sort those? There must be one function to compare every combination of value, but how do you compare string and object?

        The simple answer to that is .toString() - every object has it, it will compute something, and often it will work well enough.

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      • affiliate@lemmy.world ⁨9⁩ ⁨months⁩ ago

        thank you for the explanation, that does clarify things

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  • floofloof@lemmy.ca ⁨9⁩ ⁨months⁩ ago

    It’s also an incorrect alphabetical sort in many languages that use accented characters. For a correct sort you need to pass it something like the localeCompare function.

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• fidodo@lemm.ee ⁨9⁩ ⁨months⁩ ago

  You can put any type of value in an array in JavaScript. You can have numbers, strings, booleans, arrays, and objects. So what should the default sort function sort by? Sorting by numbers makes sense, but what if it wanted to sort strings instead?

  When you don’t know what value is in an array ahead of time you can’t assume how to sort it. When you’re controlling the program you can provide a sort function for the type of values you know will be in it, but when you’re writing the standard default sort function, there’s only one type that you can convert all the other types to safely and simply in the most predictable way, which is strings.

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• KiofKi@feddit.de ⁨9⁩ ⁨months⁩ ago

  “By default, the sort() function sorts values as strings.

  This works well for strings (“Apple” comes before “Banana”).

  However, if numbers are sorted as strings, “25” is bigger than “100”, because “2” is bigger than “1”.

  Because of this, the sort() method will produce incorrect result when sorting numbers.”

  www.w3schools.com/js/js_array_sort.asp

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  • floofloof@lemmy.ca ⁨9⁩ ⁨months⁩ ago

    It also produces incorrect results in many languages other than English. You can pass it a compare function that uses localeCompare or Intl.Collator to get a correct alphabetical sort.

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• Blackmist@feddit.uk ⁨9⁩ ⁨months⁩ ago

  Because it turns everything into text first. Just in case you try to sort [1,“apple”,45.99,false,[true,3]] rather than an array of similar things like a normal person.

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• reverendsteveii@lemm.ee ⁨9⁩ ⁨months⁩ ago

  Think of digits like you would letters. You’re essentially sorting numbers alphabetically. It’s not the right way to do it, of course, but it’s the natural way to do it using a system like computers use that doesn’t necessarily differentiate between digits and letters unless you tell it to specifically.

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  • CheezyWeezle@lemm.ee ⁨9⁩ ⁨months⁩ ago

    I think the main shortcoming here is that there isnt a way to specify the type to sort as, instead you have to write the function to compare them as numbers yourself. If it’s such a simple implementation, why isn’t it officially implemented? Why isn’t there a sortAs() that takes two args, the input list, and a Type value? Check every element matches the type and then sort, otherwise return a Type Error.

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    • reverendsteveii@lemm.ee ⁨9⁩ ⁨months⁩ ago

      I mean, there’s a sort() method that takes a comparator(a,b) such that if a comes first it returns 1, if b comes first it returns -1 and if they’re equivalent wrt sortinf it returns 0.

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      • CheezyWeezle@lemm.ee ⁨9⁩ ⁨months⁩ ago

        Right, but you have to make that comparator yourself, it’s not a built-in part of the language. The only built-in comparator converts values to strings and compares them in code units orders.

        Also, that technically isnt type-safe, is it? If you threw a string or a NaN at that it would fail. As far as I knew, type safe means that a function can handle type errors itself, rather than throwing an exception. So in this case the function would automatically convert types if it was type-safe to prevent an unhandled exception.

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• jormaig@programming.dev ⁨9⁩ ⁨months⁩ ago

  Because when it’s sorting some of them as ints and some of them as strings. JavaScript has implicit conversion to string.

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• nero@lemmy.world ⁨9⁩ ⁨months⁩ ago

  It sorts them based on their unicode character, not the actual numbers. 1 is U+0031, 2 is U+0032, etc.

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• jdeath@lemm.ee ⁨9⁩ ⁨months⁩ ago

  it’s lexicographic order

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