6 ms·

return string[0] === string[0].toUpperCase(); You're welcome!

• Arnavion 11y ago
  TIL 1 is a capital letter.
  • sspiff 11y ago
    string[0] === string[0].toUpperCase() && string[0].toUpperCase() != string[0].toLowerCase();
    • deadowl 11y ago
      typeof string == "string" && string.length && string[0] == string[0].toUpperCase() && string[0].toUpperCase() != string[0].toLowerCase();
      • sspiff 11y ago
        Man, Javascript is AWESOME.
        • deadowl 11y ago
          /\p{Lt}/.test(str) would be much more compact, but Unicode properties still aren't available in Javascript regular expressions. It doesn't look like they will be anytime soon. I guess they have some staging system and it's still at stage 0 (https://github.com/tc39/ecma262/blob/master/stage0.md https://github.com/tc39/ecma262/blob/master/stage0.md), grouped with lookbehind assertions, named captures, and mode modifiers.
• JD557 11y ago
  Not that I agree with micro modules (I would rather see a set of js core libs), but your code fails with empty strings.
  • dagw 11y ago
    That code fails in a whole host of cases, kind of proving that sometimes trivial "just one line" functions aren't actual that trivial to get right. edit: fortunately there's an npm modules you can included to fix it...
  • bewo001 11y ago
    Maybe F1axs knows that at this particular spot the string will never be empty? There are two philosophies in libraries; one is to check for every possible error in the lib function, the other is to state the pre-conditions in the documentation.
  • nailer 11y ago
    > Not that I agree with micro modules (I would rather see a set of js core libs) Why not both? If you just want one part of a module, you can just import the dependency directly, if you want a whole core lib, you can do that. Some people really like underscore and import that. I use ES6/7 functions for the most part, but underscore has some useful things I can import on their own.
• majewsky 11y ago
  This will give startsWithCapitalLetter("!") == true which is not what you want.
• heinrich5991 11y ago
  string[0] isn't necessarily one code point.
• golergka 11y ago
  > var isCapital function(s) { return s[0] === s[0].toUpperCase(); }; > isCapital("שלום"); true > isCapital("1"); true > isCapital('\uD83D\uDE00'); // Smiling emoji true > isCapital(\u279B); // Right-facing arrow true > isCapital("\u061Casd"); //Bidirectional control character true > isCapital(" "); true
  • gvdp 11y ago
    If "true" is not a valid answer, what would've been one? Similar code in C# returns the same. E.g. Console.WriteLine("שלום".ToUpperInvariant()=="שלום") returns true.
    • golergka 11y ago
      Hebrew doesn't have upper and lower case, so the question "is this hebrew character capital" is meaningless. So, the function in question should not return just a boolean value; it should have a way to return a third option. (Whether it's nil, a C-style return code, an exception, an enum or something else is irrelevant here.) Actually, it just means that if you're wondering "if this word starts with a capital", you're asking a wrong question. Instead, you should be asking "if this word is a valid generic name", or "is this word a start of a new sentence", and implement these semantic queries in a language-specific way.
      • deadowl 11y ago
        You have final-forms in Hebrew, although probably not at the same level of support for checking as you'd get with a script like Arabic.
        • golergka 11y ago
          That's true, but I don't think that sofits should be viewed as capital/not-capital letters: they're not semantically altering the meaning of the word in wider context, like capital letters do.
• DrJokepu 11y ago
  WRONG. Typical junior developer mistake. Even if we disregard trivial problems such as non-letter input or empty input, this will only work with English and a few other languages. This will TOTALLY fail with e.g. Turkish input (I ı vs İ i).
  • laserbeam 11y ago
    Not really. (string[0] == string[0].toUpperCase() && string[0] != string[0].toLowerCase()) is the correct way to approach this problem. If toUpperCase() and toLowerCase() don't handle Turkish letters, then that's a BUG in those methods, which should be reported and someone should freaking take responsibility for them and fix them. Adding another module with a method does not fix the original problem, it just creates more problems for other people to solve.