How to Sort Strings in Javascript
I Have a List of Objects I Wish to Sort Based on a Field Attr of Type String. I Tried Using - List. Sort(Function (A, B) { Return A. Attr - B. Attr }) but...
I have a list of objects I wish to sort based on a field attr of type string. I tried using -
list.sort(function (a, b) {
return a.attr - b.attr
})
but found that - doesn't appear to work with strings in JavaScript. How can I sort a list of objects based on an attribute with type string?
16 Answers
Use String.prototype.localeCompare a per your example:
list.sort(function (a, b) {
return ('' + a.attr).localeCompare(b.attr);
})
We force a.attr to be a string to avoid exceptions. localeCompare has been supported since Internet Explorer 6 and Firefox 1. You may also see the following code used that doesn't respect a locale:
if (item1.attr < item2.attr)
return -1;
if ( item1.attr > item2.attr)
return 1;
return 0;
An updated answer (October 2014)
I was really annoyed about this string natural sorting order so I took quite some time to investigate this issue. I hope this helps.
Long story short
localeCompare() character support is badass, just use it.
As pointed out by Shog9, the answer to your question is:
return item1.attr.localeCompare(item2.attr);
Bugs found in all the custom javascript "natural string sort order" implementations
There are quite a bunch of custom implementations out there, trying to do string comparison more precisely called "natural string sort order"
When "playing" with these implementations, I always noticed some strange "natural sorting order" choice, or rather mistakes (or omissions in the best cases).
Typically, special characters (space, dash, ampersand, brackets, and so on) are not processed correctly.
You will then find them appearing mixed up in different places, typically that could be:
- some will be between the uppercase 'Z' and the lowercase 'a'
- some will be between the '9' and the uppercase 'A'
- some will be after lowercase 'z'
When one would have expected special characters to all be "grouped" together in one place, except for the space special character maybe (which would always be the first character). That is, either all before numbers, or all between numbers and letters (lowercase & uppercase being "together" one after another), or all after letters.
My conclusion is that they all fail to provide a consistent order when I start adding barely unusual characters (ie. characters with diacritics or charcters such as dash, exclamation mark and so on).
Research on the custom implementations:
Natural Compare Lite: Fails at sorting consistently and , basic latin characters sortingNatural Sort: Fails at sorting consistently, see issue and see basic latin characters sortingJavascript Natural Sort: seems rather neglected since February 2012, Fails at sorting consistently, see issueAlphanum, Fails at sorting consistently, see
Browsers' native "natural string sort order" implementations via localeCompare()
localeCompare() oldest implementation (without the locales and options arguments) is supported by IE6+, see (v=vs.94).aspx (scroll down to localeCompare() method).
The built-in localeCompare() method does a much better job at sorting, even international & special characters.
The only problem using the localeCompare() method is that "the locale and sort order used are entirely implementation dependent". In other words, when using localeCompare such as stringOne.localeCompare(stringTwo): Firefox, Safari, Chrome & IE have a different sort order for Strings.
Research on the browser-native implementations:
- - basic latin characters comparison with localeCompare() - basic latin characters comparison with localeCompare() for testing on IE8
- - basic latin characters in string comparison : consistency check in string vs when a character is alone
- - IE11+ supports the new locales & options arguments
Difficulty of "string natural sorting order"
Implementing a solid algorithm (meaning: consistent but also covering a wide range of characters) is a very tough task. UTF8 contains more than 2000 characters & covers more than 120 scripts (languages). Finally, there are some specification for this tasks, it is called the "Unicode Collation Algorithm", which can be found at . You can find more information about this on this question I posted
Alexander Ross has covered the video game industry for a decade, writing deep dives on game design, esports tournaments, VR developments, and gaming culture.
