» Javascript equivalent for PHP's base64_decode

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: base64_decode.

PHP base64_decode

Description

base64_decode - Decodes data encoded with MIME base64

string base64_decode( string data [, bool strict] )

Decodes a base64 encoded data.

Parameters

  • data

    The decoded data.

  • strict

    Returns FALSE if input contains space or some other separator.

Return Values

Returns the original data or FALSE on failure. The returned data may be binary.

See Also

Javascript base64_decode

Source

This is the main source of the Javascript version of PHP's base64_decode

function base64_decode( data ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Tyler Akins (http://rumkin.com)
    // +   improved by: Thunder.m
    // +      input by: Aman Gupta
    // +   improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)    
    // -    depends on: utf8_decode
    // *     example 1: base64_decode('S2V2aW4gdmFuIFpvbm5ldmVsZA==');
    // *     returns 1: 'Kevin van Zonneveld'
    
    // mozilla has this native 
    // - but breaks in 2.0.0.12!
    //if (typeof window['btoa'] == 'function') {
    //    return btoa(data);
    //}
    
    var b64 = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
    var o1, o2, o3, h1, h2, h3, h4, bits, i = ac = 0, dec = "", tmp_arr = [];
 
    do {  // unpack four hexets into three octets using index points in b64
        h1 = b64.indexOf(data.charAt(i++));
        h2 = b64.indexOf(data.charAt(i++));
        h3 = b64.indexOf(data.charAt(i++));
        h4 = b64.indexOf(data.charAt(i++));
 
        bits = h1<<18 | h2<<12 | h3<<6 | h4;
 
        o1 = bits>>16 & 0xff;
        o2 = bits>>8 & 0xff;
        o3 = bits & 0xff;
 
        if (h3 == 64) {
            tmp_arr[ac++] = String.fromCharCode(o1);
        } else if (h4 == 64) {
            tmp_arr[ac++] = String.fromCharCode(o1, o2);
        } else {
            tmp_arr[ac++] = String.fromCharCode(o1, o2, o3);
        }
    } while (i < data.length);
    
    dec = tmp_arr.join('');
    dec = utf8_decode(dec);
    
    return dec;
}

To run the Javascript base64_decode, you will also need the following dependencies:

Examples

Currently there is 1 example

Example 1

This is how you could call base64_decode()
base64_decode('S2V2aW4gdmFuIFpvbm5ldmVsZA==');
And that would return
'Kevin van Zonneveld'

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
spacemedalSakimori for contributing to:
 strlen
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: 7,752 times

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Comments

#5. Kevin on 08 May 2008

Kevin@ Aman Gupta: The array join tip has been implemented. As far as the atob goes, thanks for providing additional information. I think for now we should stick with a version that works everywhere until we find out exactly how to safely use the native functions among different mozilla versions.

#4. Aman Gupta on 08 May 2008

Aman GuptaThis implementation is extremely slow in IE due to string concatenation. It is much faster to push onto an array and return array.join('').

In firefox, window.atob works for decoding as long as you don't pass in a large string. Over a certain size, it fails with an 'out of memory' error.

#3. Kevin on 25 April 2008

Kevin@ TXGruppi: I've added a:

// mozilla has this native
    if (typeof window['atob'] == 'function') {
        return atob(data);
    }
To make use of mozilla's native base64 functions.

#2. TXGruppi on 23 April 2008

TXGruppiI did a test in IE and not worked the functions atob and btoa, for this reason I did another test to measure the speed of implementation of tasks in Firefox and Internet Explorer. In a loop see that in the FF functions atob and btoa are faster than the functions base64_decode and base64_encode.

The test is available in http://www.txgruppi.com/base64.html

If you can send me your e-mail, I would like to discuss some issues about things I liked in your site.
... [more]
* Address of my future site.

Any questions send me an email: txgruppi@gmail.com Translated by: Google Translator

#1. TXGruppi on 08 April 2008

TXGruppiReading the functions I found the base64_encode and base64_decode in a way very complicated. There are the functions btoa and atob in JavaScript that make this conversion.

var name = 'JavaScript';
var enc = btoa(name);
var dec = atob(enc);
alert(name); // JavaScript
alert(enc); // SmF2YVNjcmlwdA==
alert(dec); // JavaScript
Any questions send me an email: txgruppi@gmail.com Translated by: Google Translator