» Javascript equivalent for PHP's crc32

PHP to Javascript Project: php.js

php.jsThis article is part of the 'Porting PHP to Javascript' Project, which aims to decrease the gap between developing for PHP & Javascript.

A lot of people are familiar with PHP's functions, and though Javascript functions are often quite similar, some functions may be missing or addressed differently. The Javascript implementations should be as compliant with the PHP versions as possible, a good indication is that the PHP function manual could also apply to the Javascript version.

Porting crucial PHP functions to Javascript can be fun & useful. Currently some PHP functions have been added, but readers are encouraged to contribute and improve functions by adding comments. Eventually the goal is to save all the functions in one php.js file and make it publicly available for your coding pleasure.

If you choose to contribute, let me know how you want to be credited in the function's comments. You may also want to subscribe to RSS so you receive updates whenever new functions are posted.

This is a Javascript version of the PHP function: crc32.

PHP crc32

Description

crc32 - Calculates the crc32 polynomial of a string

int crc32( string str )

Generates the cyclic redundancy checksum polynomial of 32-bit lengths of the str. This is usually used to validate the integrity of data being transmitted.

Parameters

  • str

    The data.

Return Values

See Also

Javascript crc32

Source

This is the main source of the Javascript version of PHP's crc32

function crc32 ( str ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Webtoolkit.info (http://www.webtoolkit.info/)
    // +   improved by: T0bsn
    // -    depends on: utf8_encode
    // *     example 1: crc32('Kevin van Zonneveld');
    // *     returns 1: 1249991249
 
    str = utf8_encode(str);
    var table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
 
    var crc = 0;
    var x = 0;
    var y = 0;
 
    crc = crc ^ (-1);
    for( var i = 0, iTop = str.length; i < iTop; i++ ) {
        y = ( crc ^ str.charCodeAt( i ) ) & 0xFF;
        x = "0x" + table.substr( y * 9, 8 );
        crc = ( crc >>> 8 ) ^ x;
    }
 
    return crc ^ (-1);
}

To run the Javascript crc32, you will also need the following dependencies:

Examples

Currently there is 1 example

Example 1

This is how you could call crc32()
crc32('Kevin van Zonneveld');
And that would return
1249991249

More about this Project

Download php.js

To easily include it in your code, every function currently available is stored in

Normal

Namespaced What is 'namespaced?'

To download use Right click, Save Link As
Generally the best way is to use a minified version and gzip it



Testing the functions

The number of functions is growing fast and so it becomes hard to maintain quality.

To defeat that danger of bad code, syntax errors, etc, I've added a new feature: php.js tester.

It is an automatically generated page that includes ALL functions in your browser, and then extracts specific testing information from each function's comments. This info is then used to run the function, and the return value is compared to a predefined one.

This way code is always checked on syntax errors, and if it doesn't function correctly anymore after an update, we should also be able to detect it more easily.

If you want, go check it out.


Credits

Respect & awards go to everybody who has contributed in some way so far:

medalmedalMichael White (link) for contributing to:
 array_count_values, get_included_files, include, include_once, require, require_once, md5, number_format, parse_str, printf, sha1, sprintf, str_pad, strnatcmp, http_build_query, floatval, is_object, print_r
spacemedal_argos for contributing to:
 array_fill, array_pad, array_product, array_rand, compact, count, range, abs, defined, ip2long, long2ip, implode, strcmp, ucwords
spacemedalJonas Raoni Soares Silva (link) for contributing to:
 shuffle, abs, setcookie, number_format, number_format, soundex, str_repeat, str_replace, str_rot13, ucwords, wordwrap, wordwrap
spacemedalLegaev Andrey for contributing to:
 end, reset, file, file_get_contents, function_exists, include, include_once, http_build_query, is_array, is_object
spacemedalAtes Goral (link) for contributing to:
 array_change_key_case, array_count_values, array_diff_key, get_class, preg_quote, addslashes, count_chars, str_rot13, stripslashes
spacemedalPhilip Peterson for contributing to:
 sizeof, round, echo, nl2br, str_replace, strchr, urldecode, urlencode, var_export
spacemedalMartijn Wieringa for contributing to:
 str_ireplace, str_split, strcasecmp, stripos, strnatcmp, substr
spacemedalWebtoolkit.info (link) for contributing to:
 crc32, md5, sha1, utf8_decode, utf8_encode
 
spacemedalCarlos R. L. Rodrigues (link) for contributing to:
 array_chunk, array_unique, date, levenshtein
spacemedalAsh Searle (link) for contributing to:
 basename, printf, sprintf
spacemedalErkekjetter for contributing to:
 ltrim, rtrim, trim
spacemedalmarrtins for contributing to:
 array_change_key_case, addslashes, stripslashes
spacemedalAlfonso Jimenez (link) for contributing to:
 array_reduce, strpbrk
spacemedalAman Gupta for contributing to:
 base64_decode, utf8_decode
spacemedalArpad Ray (mailto:arpad@php.net) for contributing to:
 serialize, unserialize
spacemedalKarol Kowalski for contributing to:
 array_reverse, abs
spacemedalThunder.m for contributing to:
 base64_decode, base64_encode
spacemedalTyler Akins (link) for contributing to:
 base64_decode, base64_encode
spacemedalmdsjack (link) for contributing to:
 include, trim
spacemedalAlexander Ermolaev (link) for contributing to:
 trim
spacemedalAllan Jensen (link) for contributing to:
 number_format
spacemedalAndrea Giammarchi (link) for contributing to:
 array_map
spacemedalBayron Guevara for contributing to:
 base64_encode
spacemedalBenjamin Lupton for contributing to:
 number_format
spacemedalBrad Touesnard for contributing to:
 date
spacemedalBrett Zamir for contributing to:
 str_split
spacemedalCagri Ekin for contributing to:
 parse_str
spacemedalCord for contributing to:
 is_array
spacemedalDavid for contributing to:
 is_numeric
spacemedalDavid James for contributing to:
 get_class
spacemedalDxGx for contributing to:
 trim
spacemedalFGFEmperor for contributing to:
 mktime
spacemedalFelix Geisendoerfer (link) for contributing to:
 array_key_exists
spacemedalFremyCompany for contributing to:
 isset
spacemedalGabriel Paderni for contributing to:
 str_replace
spacemedalLeslie Hoare for contributing to:
 rand
spacemedalLincoln Ramsay for contributing to:
 basename
spacemedalMeEtc (link) for contributing to:
 date
spacemedalMick@el for contributing to:
 stripslashes
spacemedalNick Callen for contributing to:
 wordwrap
spacemedalOzh for contributing to:
 dirname
spacemedalPedro Tainha (link) for contributing to:
 unserialize
spacemedalPeter-Paul Koch (link) for contributing to:
 date
spacemedalPhilippe Baumann for contributing to:
 empty
spacemedalSanjoy Roy for contributing to:
 array_diff
spacemedalSimon Willison (link) for contributing to:
 str_replace
spacemedalSteve Clay for contributing to:
 function_exists
spacemedalSteve Hilder for contributing to:
 strcmp
spacemedalSteven Levithan (link) for contributing to:
 trim
spacemedalT0bsn for contributing to:
 crc32
spacemedalThiago Mata (link) for contributing to:
 call_user_func_array
spacemedalTim Wiel for contributing to:
 date
spacemedalXoraX (link) for contributing to:
 dirname
spacemedalbaris ozdil for contributing to:
 mktime
spacemedalbooeyOH for contributing to:
 preg_quote
spacemedaldjmix for contributing to:
 basename
spacemedalduncan for contributing to:
 array_unique
spacemedalecho is bad for contributing to:
 echo
spacemedalgabriel paderni for contributing to:
 mktime
spacemedalger for contributing to:
 html_entity_decode
spacemedaljohn (link) for contributing to:
 html_entity_decode
spacemedalkenneth for contributing to:
 explode
spacemedalpenutbutterjelly for contributing to:
 str_ireplace
spacemedalstensi for contributing to:
 intval

Your name here?

Contributing is as easy as adding a comment with better code, or code for a new function.
Any contribution leading to improvement will directly get your name & link here.


Coming Project features

Project features that we are currently working on:

  • Versioning. Individual functions are versioned, but the entire library should be versioned as well.
  • Light. A lightweight version of php.js should be made available with only common functions in it.

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tags: programming, php, javascript
category: Programming - Javascript - PHP equivalents
read: 998 times

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Comments

#2. Kevin on 06 April 2008

Kevin@ T0bsn: I've updated the function. Thanks a lot!!

#1. T0bsn on 04 April 2008

T0bsnreplace:

if (typeof(crc) == "undefined") { crc = 0; }
with:
var crc;
...and it works for every function exec. ;)