JavaScript strnatcmp

Returns the result of string comparison using 'natural' algorithm

function strnatcmp ( f_string1, f_string2, f_version ) {
    // Returns the result of string comparison using 'natural' algorithm  
    // 
    // version: 1008.1718
    // discuss at: http://phpjs.org/functions/strnatcmp    // +   original by: Martijn Wieringa
    // + namespaced by: Michael White (http://getsprink.com)
    // +    tweaked by: Jack
    // +   bugfixed by: Onno Marsman
    // -    depends on: strcmp    // %          note: Added f_version argument against code guidelines, because it's so neat
    // *     example 1: strnatcmp('Price 12.9', 'Price 12.15');
    // *     returns 1: 1
    // *     example 2: strnatcmp('Price 12.09', 'Price 12.15');
    // *     returns 2: -1    // *     example 3: strnatcmp('Price 12.90', 'Price 12.15');
    // *     returns 3: 1
    // *     example 4: strnatcmp('Version 12.9', 'Version 12.15', true);
    // *     returns 4: -6
    // *     example 5: strnatcmp('Version 12.15', 'Version 12.9', true);    // *     returns 5: 6
    var i = 0;
 
    if (f_version == undefined) {
        f_version = false;    }
 
    var __strnatcmp_split = function ( f_string ) {
        var result = [];
        var buffer = '';        var chr = '';
        var i = 0, f_stringl = 0;
 
        var text = true;
         f_stringl = f_string.length;
        for (i = 0; i < f_stringl; i++) {
            chr = f_string.substring(i, i + 1);
            if (chr.match(/\d/)) {
                if (text) {                    if (buffer.length > 0){
                        result[result.length] = buffer;
                        buffer = '';
                    }
                     text = false;
                }
                buffer += chr;
            } else if ((text == false) && (chr == '.') && (i < (f_string.length - 1)) && (f_string.substring(i + 1, i + 2).match(/\d/))) {
                result[result.length] = buffer;                buffer = '';
            } else {
                if (text == false) {
                    if (buffer.length > 0) {
                        result[result.length] = parseInt(buffer, 10);                        buffer = '';
                    }
                    text = true;
                }
                buffer += chr;            }
        }
 
        if (buffer.length > 0) {
            if (text) {                result[result.length] = buffer;
            } else {
                result[result.length] = parseInt(buffer, 10);
            }
        } 
        return result;
    };
 
    var array1 = __strnatcmp_split(f_string1+'');    var array2 = __strnatcmp_split(f_string2+'');
 
    var len = array1.length;
    var text = true;
     var result = -1;
    var r = 0;
 
    if (len > array2.length) {
        len = array2.length;        result = 1;
    }
 
    for (i = 0; i < len; i++) {
        if (isNaN(array1[i])) {            if (isNaN(array2[i])) {
                text = true;
 
                if ((r = this.strcmp(array1[i], array2[i])) != 0) {
                    return r;                }
            } else if (text){
                return 1;
            } else {
                return -1;            }
        } else if (isNaN(array2[i])) {
            if (text) {
                return -1;
            } else{                return 1;
            }
        } else {
            if (text || f_version){
                if ((r = (array1[i] - array2[i])) != 0) {                    return r;
                }
            } else {
                if ((r = this.strcmp(array1[i].toString(), array2[i].toString())) != 0) {
                    return r;                }
            }
 
            text = false;
        }    }
 
    return result;
}

external links: original PHP docs | raw js source

Examples

» Example 1

Running

1	strnatcmp('Price 12.9', 'Price 12.15');

Should return

» Example 2

Running

1	strnatcmp('Price 12.09', 'Price 12.15');

Should return

-1

Dependencies

In order to use this function, you also need:

strcmp

Open syntax issues

php.js uses JsLint to help us keep our code consistent and prevent some common bugs.

Eventually we want all code to pass or at least take into consideration most fixes suggested by JsLint, following this JsLint configuration we’ve decided on.

Authors

Thanks to the following developers, you get to have strnatcmp goodness in JavaScript.

Martijn Wieringa ( original )
Michael White ( namespaced )
Jack ( tweaked )
Onno Marsman ( bugfixed )

Comments

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Use:

[CODE]
your_stuff('here');
[/CODE]

for proper code formatting
By submitting code here you are allowing us to use it in php.js hence dual licensing it under the MIT and GPL licenses

Kevin van Zonneveld
1 Mar '08

@ Martijn Wieringa: Though our aim has always been to copy the PHP specs of all the functions as strict as possible, I could see why you would want this functionality. And given the fact that not using the extra parameter doesn't effect it's behaviour, I will be happy to make an exception in this case. Thanks again

Martijn Wieringa
1 Mar '08

The args 'f_version' is missing in the function definition.

I've added this tag to fix the following problem:

When you're comparing numbers in a string.. like:

"Price 12.9"
"Price 12.15"

You want: "Price 12.9" > "Price 12.15".

Yet when you use numbers to indicate version numbers.. Like

"Version 12.9"
"Version 12.15"

You want: "Price 12.9" < "Price 12.15".

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