399 PHP equivalents

PHP to Javascript Project: php.js

php.js This 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: empty.

I have moved out PHP.JS to it's own site. For info & reactions on comments please goto phpjs.org

PHP empty

Description

empty - Determine whether a variable is empty

bool empty( mixed var )

Determine whether a variable is considered to be empty.

Parameters

var
Variable to be checked

Note: empty() only checks variables as anything else will result in a parse error. In other words, the following will not work: empty(trim($name)).

empty() is the opposite of (boolean) var, except that no warning is generated when the variable is not set.

Return Values

Returns FALSE if var has a non-empty and non-zero value.

The following things are considered to be empty:

"" (an empty string)
0 (0 as an integer)
"0" (0 as a string)
NULL
FALSE
array() (an empty array)
var $var; (a variable declared, but without a value in a class)

Javascript empty

Source

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

function empty( mixed_var ) {
    // http://kevin.vanzonneveld.net
    // +   original by: Philippe Baumann
    // +      input by: Onno Marsman
    // +   bugfixed by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    // +      input by: LH
    // +   improved by: Onno Marsman
    // +   improved by: Francesco
    // +   improved by: Marc Jansen
    // *     example 1: empty(null);
    // *     returns 1: true
    // *     example 2: empty(undefined);
    // *     returns 2: true
    // *     example 3: empty([]);
    // *     returns 3: true
    // *     example 4: empty({});
    // *     returns 4: true
    // *     example 5: empty({'aFunc' : function () { alert('humpty'); } });
    // *     returns 5: false
    
    var key;
    
    if (mixed_var === "" ||
        mixed_var === 0 ||
        mixed_var === "0" ||
        mixed_var === null ||
        mixed_var === false ||
        mixed_var === undefined
    ){
        return true;
    }
 
    if (typeof mixed_var == 'object') {
        for (key in mixed_var) {
            return false;
        }
        return true;
    }
 
    return false;
}

Examples

Currently there are 5 examples

Example 1

This is how you could call empty()

empty(null);

And that would return

true

Example 2

This is how you could call empty()

empty(undefined);

And that would return

true

Example 3

This is how you could call empty()

empty([]);

And that would return

true

More about this Project

Download php.js

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

Normal

uncompressed source: php.js
minified: php.min.js [recommended]
compressed: php.packed.js

Namespaced What is 'namespaced?'

uncompressed source: php.namespaced.js
minified: php.namespaced.min.js
compressed: php.namespaced.packed.js

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

Credits

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

	Brett Zamir (link) for contributing to:
	array_diff, array_diff_assoc, array_diff_key, array_diff_uassoc, array_diff_ukey, array_fill_keys, array_fill_keys, array_filter, array_intersect, array_intersect_assoc, array_intersect_key, array_intersect_uassoc, array_intersect_ukey, array_keys, array_map, array_merge, array_merge_recursive, array_pop, array_search, array_slice, array_slice, array_splice, array_udiff, array_udiff_assoc, array_udiff_uassoc, array_uintersect, array_uintersect_assoc, array_uintersect_uassoc, array_unique, arsort, arsort, asort, asort, compact, current, each, end, extract, key, krsort, ksort, natcasesort, natcasesort, natsort, natsort, next, pos, prev, reset, rsort, rsort, shuffle, sort, sort, uasort, uasort, uksort, usort, classkit_import, classkit_method_add, classkit_method_copy, classkit_method_redefine, classkit_method_remove, classkit_method_rename, class_exists, get_class_methods, get_class_vars, get_declared_classes, get_object_vars, method_exists, property_exists, ctype_alnum, ctype_alpha, ctype_cntrl, ctype_digit, ctype_graph, ctype_lower, ctype_print, ctype_punct, ctype_space, ctype_upper, ctype_xdigit, date, date, date, date, date_default_timezone_get, date_default_timezone_set, date_parse, gettimeofday, gmdate, gmmktime, gmstrftime, idate, localtime, mktime, strftime, strtotime, timezone_abbreviations_list, timezone_identifiers_list, restore_exception_handler, set_exception_handler, fclose, feof, fgetc, fgetcsv, fgets, fgetss, filemtime, fopen, fpassthru, fread, fseek, ftell, pathinfo, pclose, popen, readfile, rewind, call_user_func, call_user_func_array, create_function, func_get_arg, func_get_args, func_num_args, get_defined_functions, get_defined_functions, register_shutdown_function, assert, assert_options, get_cfg_var, get_defined_constants, get_required_files, getenv, getlastmod, ini_alter, ini_get, ini_get_all, ini_restore, ini_set, php_ini_loaded_file, php_ini_scanned_files, phpversion, putenv, set_time_limit, include, include_once, require, require_once, atan2, expm1, fmod, log1p, rand, constant, define, defined, die, exit, exit, php_strip_whitespace, sleep, time_nanosleep, time_sleep_until, usleep, gopher_parsedir, setrawcookie, aggregate, aggregate_info, aggregate_methods, aggregate_methods_by_list, aggregate_methods_by_regexp, aggregate_properties, aggregate_properties_by_list, aggregate_properties_by_regexp, aggregation_info, deaggregate, preg_grep, sql_regcase, runkit_class_adopt, runkit_class_emancipate, runkit_function_add, runkit_function_copy, runkit_function_redefine, runkit_function_remove, runkit_function_rename, runkit_import, runkit_method_add, runkit_method_copy, runkit_method_redefine, runkit_method_remove, runkit_method_rename, runkit_superglobals, chunk_split, convert_uuencode, count_chars, echo, get_html_translation_table, lcfirst, levenshtein, localeconv, md5, md5_file, nl2br, nl_langinfo, parse_str, printf, quoted_printable_decode, quoted_printable_decode, quoted_printable_encode, setlocale, sha1, soundex, sprintf, str_getcsv, str_ireplace, str_replace, str_replace, str_shuffle, str_split, str_word_count, strcoll, strcspn, strip_tags, strlen, strnatcasecmp, strncmp, strrchr, strspn, strtok, strtr, substr_compare, substr_replace, ucfirst, vprintf, base64_decode, get_headers, get_meta_tags, parse_url, rawurldecode, rawurldecode, rawurlencode, rawurlencode, rawurlencode, urldecode, urldecode, urlencode, urlencode, doubleval, get_defined_vars, get_resource_type, gettype, import_request_variables, import_request_variables, is_array, is_array, is_binary, is_buffer, is_callable, is_real, is_resource, is_unicode, print_r, print_r, settype, strval, strval, unserialize, var_dump, var_export, utf8_decode
	Onno Marsman for contributing to:
	acos, acosh, asin, asinh, atan, atanh, ceil, cos, cosh, decbin, dechex, decoct, exp, floor, fmod, getrandmax, hypot, is_finite, is_infinite, is_nan, lcg_value, log, log10, max, max, min, min, mt_getrandmax, mt_rand, pi, pow, rand, round, sin, sinh, sqrt, tan, tanh, setcookie, preg_quote, addslashes, bin2hex, count_chars, html_entity_decode, htmlentities, htmlspecialchars_decode, levenshtein, ltrim, nl2br, nl2br, ord, parse_str, rtrim, soundex, str_ireplace, str_replace, str_replace, str_rot13, str_split, strcasecmp, strip_tags, stripos, stripslashes, stristr, strlen, strnatcmp, strncasecmp, strpbrk, strpos, strrev, strripos, strrpos, strstr, strtolower, strtoupper, substr, substr_count, trim, ucfirst, ucwords, base64_decode, empty, empty, is_array, is_bool, isset, utf8_decode, utf8_encode, utf8_encode
	Michael 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, vprintf, http_build_query, floatval, is_object, print_r
	Waldo Malqui Silva for contributing to:
	array_fill, array_pad, array_product, array_rand, compact, count, range, abs, defined, ip2long, long2ip, implode, strcmp, strncmp, ucwords, settype
	Paulo Ricardo F. Santos for contributing to:
	getdate, microtime, constant, define, chop, chunk_split, quotemeta, sprintf, get_headers, gettype, is_double, is_float, is_integer, is_long, is_scalar
	Jack for contributing to:
	compact, max, min, count_chars, htmlentities, md5, parse_str, soundex, sprintf, str_ireplace, strnatcmp, trim, utf8_encode
	Jonas Raoni Soares Silva (link) for contributing to:
	shuffle, abs, setcookie, number_format, number_format, soundex, str_repeat, str_replace, str_rot13, ucwords, wordwrap, wordwrap
	Philip Peterson for contributing to:
	sizeof, log10, round, exit, echo, get_html_translation_table, nl2br, str_replace, strchr, urldecode, urlencode, var_export
	Ates Goral (link) for contributing to:
	array_change_key_case, array_count_values, array_diff_key, each, get_class, preg_quote, addslashes, count_chars, str_rot13, stripslashes
	Legaev Andrey for contributing to:
	end, reset, file, file_get_contents, function_exists, include, include_once, http_build_query, is_array, is_object
	Martijn Wieringa for contributing to:
	array_shift, array_unshift, str_ireplace, str_split, strcasecmp, stripos, strnatcmp, substr
	Nate for contributing to:
	array_merge, array_sum, array_unique, pathinfo, addslashes, echo, strncasecmp
	Enrique Gonzalez for contributing to:
	file_exists, filesize, decbin, decoct, deg2rad, rad2deg
	Philippe Baumann for contributing to:
	base_convert, bindec, dechex, hexdec, octdec, empty
	Theriault for contributing to:
	array_multisort, quoted_printable_decode, quoted_printable_decode, quoted_printable_encode, quoted_printable_encode
	Webtoolkit.info (link) for contributing to:
	crc32, md5, sha1, utf8_decode, utf8_encode

	Ash Searle (link) for contributing to:
	basename, printf, sprintf, vprintf
	Carlos R. L. Rodrigues (link) for contributing to:
	array_chunk, array_unique, date, levenshtein
	Jani Hartikainen for contributing to:
	file, file_exists, file_get_contents, filesize
	Ole Vrijenhoek for contributing to:
	convert_uuencode, convert_uuencode, quoted_printable_decode, str_word_count
	travc for contributing to:
	rawurldecode, rawurlencode, urldecode, urlencode
	Alex for contributing to:
	get_html_translation_table, strip_tags, is_int
	Andrea Giammarchi (link) for contributing to:
	array_map, define, levenshtein
	Erkekjetter for contributing to:
	ltrim, rtrim, trim
	GeekFG (link) for contributing to:
	krsort, ksort, time
	Johnny Mast (link) for contributing to:
	array_walk, array_walk_recursive, create_function
	Michael Grier for contributing to:
	array_unique, wordwrap, rawurlencode
	d3x for contributing to:
	array, explode, unserialize
	marrtins for contributing to:
	array_change_key_case, addslashes, stripslashes
	stag019 for contributing to:
	parse_str, parse_str, http_build_query
	AJ for contributing to:
	urldecode, urlencode
	Alfonso Jimenez (link) for contributing to:
	array_reduce, strpbrk
	Aman Gupta for contributing to:
	base64_decode, utf8_decode
	Arpad Ray (mailto:arpad@php.net) for contributing to:
	serialize, unserialize
	Breaking Par Consulting Inc (link) for contributing to:
	gettimeofday, localtime
	Caio Ariede (link) for contributing to:
	strtotime, strtotime
	David for contributing to:
	strtotime, is_numeric
	Josh Fraser (link) for contributing to:
	gettimeofday, localtime
	KELAN for contributing to:
	get_html_translation_table, gettype
	Karol Kowalski for contributing to:
	array_reverse, abs
	Lars Fischer for contributing to:
	urldecode, urlencode
	Marc Palau for contributing to:
	mktime, strip_tags
	Mirek Slugen for contributing to:
	htmlspecialchars, htmlspecialchars_decode
	Oleg Eremeev for contributing to:
	str_replace, str_replace
	Pellentesque Malesuada for contributing to:
	base64_decode, base64_encode
	Public Domain (link) for contributing to:
	json_decode, json_encode
	Sakimori for contributing to:
	strlen, wordwrap
	Steve Hilder for contributing to:
	strcmp, strncmp
	Steven Levithan (link) for contributing to:
	trim, parse_url
	Thunder.m for contributing to:
	base64_decode, base64_encode
	Tyler Akins (link) for contributing to:
	base64_decode, base64_encode
	gettimeofday for contributing to:
	date, idate
	gorthaur for contributing to:
	strcmp, strncmp
	mdsjack (link) for contributing to:
	include, trim
	0m3r for contributing to:
	array_diff_assoc
	Alexander Ermolaev (link) for contributing to:
	trim
	Allan Jensen (link) for contributing to:
	number_format
	Andreas for contributing to:
	setcookie
	Andrej Pavlovic for contributing to:
	serialize
	Anton Ongson for contributing to:
	str_replace
	Arno for contributing to:
	htmlspecialchars
	Atli Þór for contributing to:
	nl2br
	Bayron Guevara for contributing to:
	base64_encode
	Ben Bryan for contributing to:
	print_r
	Benjamin Lupton for contributing to:
	number_format
	Blues (link) for contributing to:
	strftime
	Blues at link for contributing to:
	setlocale
	Bobby Drake for contributing to:
	strip_tags
	Brad Touesnard for contributing to:
	date
	Bryan Elliott for contributing to:
	date
	Cagri Ekin for contributing to:
	parse_str
	ChaosNo1 for contributing to:
	timezone_abbreviations_list
	Christian Doebler for contributing to:
	sleep
	Cord for contributing to:
	is_array
	Daniel Esteban for contributing to:
	strpos
	David James for contributing to:
	get_class
	David Randall for contributing to:
	date
	Der Simon (link) for contributing to:
	echo
	Dino for contributing to:
	serialize
	Diogo Resende for contributing to:
	number_format
	Douglas Crockford (link) for contributing to:
	gettype
	DxGx for contributing to:
	trim
	Eric Nagel for contributing to:
	strip_tags
	Eugene Bulkin (link) for contributing to:
	echo
	FGFEmperor for contributing to:
	mktime
	Felix Geisendoerfer (link) for contributing to:
	array_key_exists
	Francesco for contributing to:
	empty
	Francois for contributing to:
	htmlspecialchars_decode
	FremyCompany for contributing to:
	isset
	Gabriel Paderni for contributing to:
	str_replace
	Garagoth for contributing to:
	serialize
	Gilbert for contributing to:
	array_sum
	Howard Yeend for contributing to:
	number_format
	Hyam Singer (link) for contributing to:
	exit
	J A R for contributing to:
	end
	Jalal Berrami for contributing to:
	import_request_variables
	Kirk Strobeck for contributing to:
	strlen
	Kristof Coomans (SCK-CEN (Belgian Nucleair Research Centre)) for contributing to:
	strnatcasecmp
	LH for contributing to:
	empty
	Leslie Hoare for contributing to:
	rand
	Lincoln Ramsay for contributing to:
	basename
	Linuxworld for contributing to:
	bin2hex
	Luke Godfrey for contributing to:
	strip_tags
	Luke Smith (link) for contributing to:
	number_format
	Manish for contributing to:
	is_array
	Marc Jansen for contributing to:
	empty
	Marco for contributing to:
	get_html_translation_table
	Martin Pool for contributing to:
	strnatcasecmp
	Mateusz "loonquawl" Zalega for contributing to:
	htmlspecialchars_decode
	Matt Bradley for contributing to:
	is_int
	MeEtc (link) for contributing to:
	date
	Mick@el for contributing to:
	stripslashes
	Nathan for contributing to:
	htmlspecialchars
	Nick Callen for contributing to:
	wordwrap
	Norman "zEh" Fuchs for contributing to:
	utf8_decode
	Ole Vrijenhoek (link) for contributing to:
	filemtime
	Ozh for contributing to:
	dirname
	Paul for contributing to:
	exit
	Pedro Tainha (link) for contributing to:
	unserialize
	Peter-Paul Koch (link) for contributing to:
	date
	Pierre-Luc Paour for contributing to:
	strnatcasecmp
	Pul for contributing to:
	strip_tags
	Pyerre for contributing to:
	checkdate
	ReverseSyntax for contributing to:
	htmlspecialchars_decode
	Rival for contributing to:
	number_format
	Robin for contributing to:
	is_nan
	Sanjoy Roy for contributing to:
	array_diff
	Saulo Vallory for contributing to:
	strncasecmp
	Scott Cariss for contributing to:
	htmlspecialchars_decode
	Simon Willison (link) for contributing to:
	str_replace
	Slawomir Kaniecki for contributing to:
	htmlspecialchars_decode
	Soren Hansen for contributing to:
	count
	Steve Clay for contributing to:
	function_exists
	Subhasis Deb for contributing to:
	array_merge_recursive
	T. Wild for contributing to:
	filesize
	T.Wild for contributing to:
	substr
	T0bsn for contributing to:
	crc32
	Thiago Mata (link) for contributing to:
	call_user_func_array
	Tim Wiel for contributing to:
	date
	Tim de Koning for contributing to:
	is_numeric
	Tod Gentille for contributing to:
	log10
	Valentina De Rosa for contributing to:
	strspn
	Victor for contributing to:
	ip2long
	Wagner B. Soares for contributing to:
	strtotime
	XoraX (link) for contributing to:
	dirname
	YUI Library: link for contributing to:
	setlocale
	Yannoo for contributing to:
	mktime
	Yves Sucaet for contributing to:
	utf8_encode
	baris ozdil for contributing to:
	mktime
	booeyOH for contributing to:
	preg_quote
	class_exists for contributing to:
	get_declared_classes
	date for contributing to:
	idate
	djmix for contributing to:
	basename
	dptr1988 for contributing to:
	unserialize
	duncan for contributing to:
	array_unique
	echo is bad for contributing to:
	echo
	ejsanders for contributing to:
	vsprintf
	gabriel paderni for contributing to:
	mktime
	ger for contributing to:
	html_entity_decode
	hitwork for contributing to:
	utf8_decode
	jakes for contributing to:
	mktime
	john (link) for contributing to:
	html_entity_decode
	johnrembo for contributing to:
	var_export
	kenneth for contributing to:
	explode
	madipta for contributing to:
	get_html_translation_table
	marc andreu for contributing to:
	html_entity_decode
	metjay for contributing to:
	time
	mk.keck for contributing to:
	realpath
	mktime for contributing to:
	gmmktime
	nobbler for contributing to:
	htmlentities
	noname for contributing to:
	get_html_translation_table
	penutbutterjelly for contributing to:
	str_ireplace
	rezna for contributing to:
	stripslashes
	sankai for contributing to:
	array_count_values
	setcookie for contributing to:
	setrawcookie
	sowberry for contributing to:
	utf8_encode
	stensi for contributing to:
	intval
	strcasecmp, strcmp for contributing to:
	substr_compare
	taith for contributing to:
	is_numeric
	uestla for contributing to:
	strtr

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:

Done - Site. A place for php.js of it's own. See: phpjs.org.
Done - Compile. Compile your own php.js version, with only the functions you need. Should generate a hash with which you can retrieve latest versions of your php.js combination.

Done - Testsuite

Done - Versioning. Individual functions are versioned, but the entire library should be versioned as well.

Stay up to date

You can track my blog articles and comments. You may also find my bookmarks interesting. Or twitter Follow me on Twitter

Like this article?

Then Dzone it!
Or use another bookmark button below to show your support &
help me spread the word.

Articles like this one

» PHP.JS Licensing
» PHP.JS Namespaced
» PHP.JS SVN
» Get an article's Digg count in PHP
» Create daemons in PHP

tags: programming, php, javascript
category: Programming - Javascript - PHP equivalents
read: 12,814 times

Add Comment

PHP.JS is outgroing this blog and moving to it's own space. Please leave your comment here: http://phpjs.org/functions/empty

Comments

#11. Kevin on 04 March 2009

Member avatar: Kevin @ Marc Jansen: Fixed in svn, thank you!

#10. Marc Jansen on 03 March 2009

Nice work folks, but I think I found a bug: shouldn't the following code yield 'false'?

var anObj = { 
  'aFunc' : function () { alert('humpty'); } 
}; 
alert( empty( anObj ) ); // alerts true, but the object contains an element

This is IMHO wrong for arrays as well:

var anArr = [ 
  function () { alert( 'dumpty' ); } 
]; 
alert( empty( anArr ) ) ; // alerts true, but the array contains an element

Named functions should behave the same.

#9. Kevin on 11 February 2009

Member avatar: Kevin @ Brett Zamir: wicked

#8. Brett Zamir on 10 February 2009

If it's all right, Kevin, I'll change the text for !== 'function' to be a test for whether o.hasOwnProperty(i). That solves the prototype problem (though even that might be considered non-empty) but avoids the current issue of considering this to be empty: var o = {method:function(){}}

#7. Kevin on 03 November 2008

Member avatar: Kevin @ Francesco: I've committed your improvement, and credited you accordingly, thanks

#6. Francesco on 26 October 2008

If you extend the Array or Object prototype, empty([]) and empty({}) return true...

i've added
if (typeof mixed_var[key] !== 'function' )
this test before returning false in the for cicle, thanks

#5. Kevin on 06 October 2008

Member avatar: Kevin @ Onno Marsman: Excellent thought and well executed Onno!

#4. Onno Marsman on 06 October 2008

typeof array will be 'object' so the check for 'array' maxes no sense:

function empty( mixed_var ) {
    if (mixed_var === ""
        || mixed_var === 0
        || mixed_var === "0"
        || mixed_var === null
        || mixed_var === false
        || mixed_var === undefined
        || (mixed_var instanceof Array && mixed_var.length === 0)
    ) {
        return true;
    }

Something else: what about empty({}) ?
If you consider {} an object as in PHP then it will never be empty. But I would never use it like that. It would make more sense to call empty({}) when {} could be considered as an associative array, and in that case it is empty and should return true:

function empty( mixed_var ) {
    if (mixed_var === ""
        || mixed_var === 0
        || mixed_var === "0"
        || mixed_var === null
        || mixed_var === false
        || mixed_var === undefined
    ){
        return true;
    }
    if (typeof mixed_var == 'object') {
        for (var i in mixed_var) {
            return false;
        }
        return true;
    }
    return false;
}

Note that in this implementation I removed the line that handles arrays because the section that takes care of objects handles this correctly for arrays anyway.