14

I am trying to sort an array of object by a property title. This the code snippet that I am running but it does not sort anything. The array is displayed as it is. P.S I looked at previous similar questions. This one for example here suggests and uses the same method I am using.

The javascript:

function sortLibrary() { // var library is defined, use it in your code // use console.log(library) to output the sorted library data console.log("inside sort"); library.sort(function(a,b){return a.title - b.title;}); console.log(library); } // tail starts here var library = [ { author: 'Bill Gates', title: 'The Road Ahead', libraryID: 1254 }, { author: 'Steve Jobs', title: 'Walter Isaacson', libraryID: 4264 }, { author: 'Suzanne Collins', title: 'Mockingjay: The Final Book of The Hunger Games', libraryID: 3245 } ]; sortLibrary();

The html code:

<html> <head> <meta charset="UTF-8"> </head> <body> <h1> Test Page </h1> <script src="myscript.js"> </script> </body> </html>
Improve this question
1
  • "Bill Gates" - "Steve Jobs" should be what? Infinity or rather Not a Number ;)?
    – Jonas Wilms
    CommentedAug 28, 2017 at 18:01

5 Answers 5

Reset to default
16

Have you tried like this? It is working as expected

library.sort(function(a,b) {return (a.title > b.title) ? 1 : ((b.title > a.title) ? -1 : 0);} ); 

var library = [ { author: 'Bill Gates', title: 'The Road Ahead', libraryID: 1254 }, { author: 'Steve Jobs', title: 'Walter Isaacson', libraryID: 4264 }, { author: 'Suzanne Collins', title: 'Mockingjay: The Final Book of The Hunger Games', libraryID: 3245 } ]; console.log('before sorting...'); console.log(library); library.sort(function(a,b) {return (a.title > b.title) ? 1 : ((b.title > a.title) ? -1 : 0);} ); console.log('after sorting...'); console.log(library);

Improve this answer
1
  • Is there any way to order this non-alphabetically, but based on another pre-set array? For example, order an entire list of names and functions but in the order of a pre-set array of functions ( chef above sous-chef, above chef de parties, ... ).
    – nclsvh
    CommentedMar 21, 2022 at 7:46
4

Subtraction is for numeric operations. Use a.title.localeCompare(b.title) instead.

function sortLibrary() { console.log("inside sort"); library.sort(function(a, b) { return a.title.localeCompare(b.title); }); console.log(library); } var library = [{ author: 'Bill Gates', title: 'The Road Ahead', libraryID: 1254 }, { author: 'Steve Jobs', title: 'Walter Isaacson', libraryID: 4264 }, { author: 'Suzanne Collins', title: 'Mockingjay: The Final Book of The Hunger Games', libraryID: 3245 } ]; sortLibrary();

Improve this answer
    2

    Use the < or > operator when comparing strings in your compare function.

    see documentation

    Improve this answer
    4
    • 1
      Use the > operator for this instance, this works when replacing the minus operator with >.
      – jonathan.ihm
      CommentedAug 28, 2017 at 18:04
    • 1
      @jonathan.ihm: The .sort() callback expects a numeric result, not a boolean, so more than just a drop-in replacement would be needed.
      – spanky
      CommentedAug 28, 2017 at 18:11
    • I ran it in console and confirmed it worked right away. See also stackoverflow.com/questions/51165/…
      – jonathan.ihm
      CommentedAug 28, 2017 at 18:14
    • Nevermind, see stackoverflow.com/questions/34466125/… as well I stand corrected.
      – jonathan.ihm
      CommentedAug 28, 2017 at 18:20
    0

    you can try this code from https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/sort

    library.sort(function(a, b){ var tA = a.title.toUpperCase(); var tB = b.title.toUpperCase(); if (tA < tB) { return -1; } if (tA > tB) { return 1; } return 0; })
    Improve this answer
      -1

      Can you try this

      FOR DESC

      library.sort(function(a,b){return a.title < b.title;});

      or FOR ASC

      library.sort(function(a,b){return a.title > b.title;});
      Improve this answer

        Start asking to get answers

        Find the answer to your question by asking.

        Ask question

        Explore related questions

        See similar questions with these tags.