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empty & Détermine si une variable est vide
Description
bool empty
Liste de paramètres
Variable à vérifier.
Avant PHP 5.5, la fonction empty() ne supportait
tout autre type retournait une erreur d'analyse.
En d'autres termes, ce qui suit ne fonctionnait pas :
empty(trim($name)). A la place, utilisez
trim($name) == false.
Aucune alerte n'est générée si la variable n'existe pas. Cela signifie que
empty() est strictement équivalent à
!isset($var) || $var == false.
Valeurs de retour
Retourne FALSE si var existe et est non-vide,
et dont la valeur n'est pas zéro.
Ce qui suit est considéré comme étant vide :
&& (une cha?ne vide)
0 (0 en tant qu'entier)
0.0 (0 en tant que nombre à virgule flottante)
&0& (0 en tant que cha?ne de caractères)
array() (un tableau vide)
$ (une variable déclarée, mais sans valeur)
Historique
Exemple #1
Une comparaison simple empty() / .
&?php$var&=&0;&&&&&&&&&&&&&&&&&&&//&Evalué&à&vrai&car&$var&est&videif&(empty($var))&{&&echo&'$var&vaut&soit&0,&vide,&ou&pas&définie&du&tout';}&&&&&&&&&&&&&&&&&&&//&Evalué&à&vrai&car&$var&est&définiif&(isset($var))&{&&echo&'$var&est&définie&même&si&elle&est&vide';}?&
Exemple #2 empty() sur des positions dans une cha?ne
PHP 5.4 modifie le comportement de la fonction
empty() lors de l'utilisation
de positions dans une cha?ne.
&?php$expected_array_got_string&=&'somestring';var_dump(empty($expected_array_got_string['some_key']));var_dump(empty($expected_array_got_string[0]));var_dump(empty($expected_array_got_string['0']));var_dump(empty($expected_array_got_string[0.5]));var_dump(empty($expected_array_got_string['0.5']));var_dump(empty($expected_array_got_string['0&Mostel']));?&
Résultat de l'exemple ci-dessus en PHP 5.3 :
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
bool(false)
Résultat de l'exemple ci-dessus en PHP 5.4 :
bool(true)
bool(false)
bool(false)
bool(false)
bool(true)
bool(true)
Note: Comme ceci est une structure
du langage, et non pas une fonction, il n'est pas possible de l'appeler
avec les .
Lors de l'utilisation de cette fonction sur des propriétés d'objet
inaccessibles, la méthode magique
sera appelée, si elle existe.
Voir aussi
- D&termine si une variable est d&finie et est diff&rente de NULL
- D&truit une variable
- V&rifie si une cl& existe dans un tableau
- Compte tous les &l&ments d'un tableau ou quelque chose d'un objet
- Calcule la taille d'une cha&ne
Please note that results of empty() when called on non-existing / non-public variables of a class are a bit confusing if using magic method __get (as previously mentioned by nahpeps at gmx dot de). Consider this example:&?phpclass Registry{& & protected $_items = array();& & public function __set($key, $value)& & {& & & & $this-&_items[$key] = $value;& & }& & public function __get($key)& & {& & & & if (isset($this-&_items[$key])) {& & & & & & return $this-&_items[$key];& & & & } else {& & & & & & return null;& & & & }& & }}$registry = new Registry();$registry-&empty = '';$registry-&notEmpty = 'not empty';var_dump(empty($registry-&notExisting)); var_dump(empty($registry-&empty)); var_dump(empty($registry-&notEmpty)); $tmp = $registry-&notEmpty;var_dump(empty($tmp)); ?&The result for empty($registry-&notEmpty) is a bit unexpeced as the value is obviously set and non-empty. This is due to the fact that the empty() function uses __isset() magic functin in these cases. Although it's noted in the documentation above, I think it's worth mentioning in more detail as the behaviour is not straightforward. In order to achieve desired (expexted?) results, you need to add& __isset() magic function to your class:&?phpclass Registry{& & protected $_items = array();& & public function __set($key, $value)& & {& & & & $this-&_items[$key] = $value;& & }& & public function __get($key)& & {& & & & if (isset($this-&_items[$key])) {& & & & & & return $this-&_items[$key];& & & & } else {& & & & & & return null;& & & & }& & }& & public function __isset($key)& & {& & & & if (isset($this-&_items[$key])) {& & & & & & return (false === empty($this-&_items[$key]));& & & & } else {& & & & & & return null;& & & & }& & }}$registry = new Registry();$registry-&empty = '';$registry-&notEmpty = 'not empty';var_dump(empty($registry-&notExisting)); var_dump(empty($registry-&empty)); var_dump(empty($registry-&notEmpty)); ?&It actually seems that empty() is returning negation of the __isset() magic function result, hence the negation of the empty() result in the __isset() function above.
I'm summarising a few points on empty() with inaccessible properties, in the hope of saving others a bit of time. Using PHP 5.3.2.&?phpclass MyClass {& & private $foo = 'foo';}$myClass = new MyClass;echo $myClass-&foo;?&As expected, this gives "Fatal error: Cannot access private property MyClass::$foo".But substitute the lineif (empty($myClass-&foo)) echo 'foo is empty'; else echo 'foo is not empty';and we get the misleading result "foo is empty". There is NO ERROR OR WARNING, so this is a real gotcha. Your code will just go wrong silently, and I would say it amounts to a bug.If you add two magic functions to the class:public function __get($var) { return $this-&$ }public function __isset($var) { return isset($this-&$var); }then we get the expected result. You need both functions.For empty($myClass-&foo), I believe PHP calls __isset, and if that is true returns the result of empty on the result of __get. (Some earlier posts wrongly suggest PHP just returns the negation of __isset).BUT …See the earlier post by php at lanar dot com. I confirm those results, and if you extend the test with isset($x-&a-&b-&c) it appears that __isset is only called for the last property in the chain. Arguably another bug. empty() behaves in the same way. So things are not as clear as we might hope.See also the note on empty() atClear as mud!
When you need to accept these as valid, non-empty values:- 0 (0 as an integer)- 0.0 (0 as a float)- "0" (0 as a string)&?phpfunction is_blank($value) {& & return empty($value) && !is_numeric($value);}?&This is similar to Rails' blank? method.
test if all multiarray's are empty
&?php
function is_multiArrayEmpty($multiarray) {
& & if(is_array($multiarray) and !empty($multiarray)){
& & & & $tmp = array_shift($multiarray);
& & & & & & if(!is_multiArrayEmpty($multiarray) or !is_multiArrayEmpty($tmp)){
& & & & & & & & return false;
& & & & & & }
& & & & & & return true;
& & }
& & if(empty($multiarray)){
& & & & return true;
& & }
& & return false;
}
$testCase = array (& &&
0 =& '',
1 =& "",
2 =& null,
3 =& array(),
4 =& array(array()),
5 =& array(array(array(array(array())))),
6 =& array(array(), array(), array(), array(), array()),
7 =& array(array(array(), array()), array(array(array(array(array(array(), array())))))),
8 =& array(null),
9 =& 'not empty',
10 =& "not empty",
11 =& array(array("not empty")),
12 =& array(array(),array("not empty"),array(array()))
);
foreach ($testCase as $key =& $case ) {
& & echo "$key is_multiArrayEmpty= ".is_multiArrayEmpty($case)."&br&";
}
?&
OUTPUT:
========
0 is_multiArrayEmpty= 1
1 is_multiArrayEmpty= 1
2 is_multiArrayEmpty= 1
3 is_multiArrayEmpty= 1
4 is_multiArrayEmpty= 1
5 is_multiArrayEmpty= 1
6 is_multiArrayEmpty= 1
7 is_multiArrayEmpty= 1
8 is_multiArrayEmpty= 1
9 is_multiArrayEmpty=
10 is_multiArrayEmpty=
11 is_multiArrayEmpty=
12 is_multiArrayEmpty=
&?php$str = '& & & & & & ';var_dump(empty($str)); ?&So remember to trim your strings first!&?php$str = '& & & & ';$str = trim($str);var_dump(empty($str)); ?&
(experienced in PHP 5.6.3) The `empty()` can't evaluate `__get()` results explicitly, so the `empty()` statement bellow always renders true&?phpclass Juice extends Liquid{&& protected $apple;&& protected $orange;&& public function __get($name) {& & & return $this-&$name;&& }&& public function __construct($apple, $orange) {& & & $this-&apple = $apple;& & & $this-&orange = $orange;&& }}class Glass {&& protected $liquid;&& public function __get($name) {& & & return $name == "liquid" ? $this-&liquid : false;&& }&& public function __construct() {& & & $this-&juice = new Juice(3, 5);&& }}$glass = new Glass();var_dump(empty($this-&liquid-&apple));?&The correct way is to force the evaluation of `__get()` first, by using extra braces around implicit statements like this:&?phpvar_dump(empty(($this-&liquid-&apple)));?&So if you are using packages that utilize object oriented designs and magic methods like `__get()`, it's a good practice to always use double braces for `empty()` calls.
Note that checking the existence of a subkey of an array when that subkey does not exist but the parent does and is a string will return false for empty.
&?php
$params = array('search'=&'1');
empty($params['search']['filter']); ?&
This is correct, per the documentation (); quite a bit down the page is the Warning: "Writing to an out of range offset pads the string with spaces. Non-integer types are converted to integer." ) I didn't receive a warning but perhaps that's correct too...depends on whether the string -& integer conversion is considered "illegal": "Illegal offset type emits E_NOTICE."
(i.e. since $params['search'] is a string, the 'filter' subscript is converted to 0, so the test becomes empty($params['search'][0]), which is obviously false), but it tripped me up enough to mistakenly file a bug report (which I've since closed).
If you want to use empty() to evaluate an expression (not a variable), and you don't have PHP 5.5+, you can do it by wrapping the call to empty in a function, like so:&?phpfunction is_empty($var) {& & return empty($var);}?&Then you can do something like&?phpif(is_empty(NULL)) { }?&without issue, since the local variable $var is being tested rather than the expression in the function call itself.
Here's what I do for the zero issue issue:if($val == '' && $val !== 0 && $val !== '0')
In reply to "admin at ninthcircuit dot info",Using str_replace is unnecessary. I would encourage the use of trim which would most likely be faster (haven't tested) and easier. Trim also takes care of other white space like line breaks and tabs. Actually, in most of the applications I code, I use a multi-dimensional array map function with trim on the Super Globals such as $_POST, $_GET and $_COOKIE as so far, there hasn't been an instance where I would want any user input to begin or end with whitespace. The good thing about doing this is that you never have to worry about 'trimming' your input which makes your code easier and more reliable (incase you forget to trim some input).
To add on to what anon said, what's happening in john_jian's example seems unusual because we don't see the implicit typecasting going on behind the scenes.& What's really happening is:$a = '';$b = 0;$c = '0';(int)$a == $b -& true, because any string that's not a number gets converted to 0$b==(int)$c -& true, because the int in the string gets convertedand$a==$c -& false, because they're being compared as strings, rather than integers.& (int)$a==(int)$c should return true, however.Note: I don't remember if PHP even *has* typecasting, much less if this is the correct syntax.& I'm just using something for the sake of examples.
I can't use empty() in all situations because '0' is usually not considered empty to me. I did a quick benchmark over the most common ways of testing it. '' == var suffers from '' == 0 is true so that's just there for curiosity.
&?php
& & $microtimeref = microtime(true);
& & $a = 0;
& & $b = 'asd';
& & for ($i = 0; $i & 5000000; $i++)
& & {
& & & & if (0 == mb_strlen ($b))
& & & & {
& & & & & & $a++;
& & & & }
& & }
& & echo "Total time 0 == mb_strlen(var): &b&" . round(microtime(true) - $microtimeref,3) . 's&/b&&br /&';
?&
The results:
Total time 0 == mb_strlen(var): 3.141s
Total time 0 === strlen(var): 2.904s
Total time 0 == strlen(var): 2.878s
Total time '' == var: 1.774s
Total time '' === var: 1.706s
Total time empty(var): 1.496s
Thus '' === var will be my zero length string test.
Calling non existing object property, empty($object-&prop), will trigger __isset(), the same way as isset($object-&prop) does, but there is one difference. If __isset() returns TRUE, another call to __get() will be made and actual return value will be result of empty() and result of __get().
Note on the selfmade empty function below:function_exists() returns false on language constructs and empty is a language construct.
Since I didn't like how empty() considers 0 and "0" to be empty (which can easily lead to bugs in your code), and since it doesn't deal with whitespace, i created the following function:&?phpfunction check_not_empty($s, $include_whitespace = false){& & if ($include_whitespace) {& & & & $s = trim($s);& & }& & return (isset($s) && strlen($s)); }?&Instead of saying if (!empty($var)) { // it's not empty } you can just say if (check_not_empty($var)) { // it's not empty }.If you want strings that only contain whitespace (such as tabs or spaces) to be treated as empty then do: check_not_empty($var, 1)If you want to check if a string IS empty then do: !check_not_empty($var).So, whenever you want to check if a form field both exists and contains a value just do: if (check_not_empty($_POST['foo'], 1))no need to do if (isset() && !empty()) anymore =]
Be careful, if "0" (zero as a string), 0 (zero as an integer) and -0 (minus zero as an integer) return true, "-0" (minus zero as a string (yes, I already had some customers that wrote -0 into a form field)) returns false. You need to cast your variable before testing it with the empty() function :&?php$var = "-0";echo empty($var);& $var = (int) $var; echo empty($vat);& ?&
To make an empty function, which only accepts arrays, one can use type-hinting:
&?php
function emptyArray(array $xs){
return empty($xs);
}
?&
Type hinting is a good thing to use in your code, because it makes it more easy to reason about your code. Besides that, it automatically documents the code.
empty() should not necessarily return the negation of the __isset() magic function result, if you set a data member to 0, isset() should return true and empty should also return true.& A simpler implementation of the __isset magic function would be:public function __isset($key) {& return isset($this-&{$key});}I don't understand why this isn't included in stdClass and inherited by default.
empty($var) will return TRUE if $var is empty (according to the definition of 'empty' above) AND if $var is not set.I know that the statement in the "Return Values" section of the manual already says this in reverse:"Returns FALSE if var has a non-empty and non-zero value." but I was like "Why is this thing returning TRUE for unset variables???"... oh i see now... Its supposed to return TRUE for unset variables!!!&?php& ini_set('error_reporting',E_ALL);& ini_set('display_errors','1');& empty($var);?&
Simple solution for: "Fatal error: Can't use function return value in write context in ..."&?phpfunction _empty($val) { return empty($val); }?&
When using the php empty() function to check submitted variables such as $_POST or $_GET, be careful to remember that values 0 (integer) and "0" (string with zero character) are all considered empty. eg. in a simple cms a page ID of zero might be used to indicate that the homepage should be displayed but using the following code:&?phpif (isset($_GET['pid'] && !empty($_GET['pid']) {& $pageID = $_GET['pid'];} else {& echo "missing variable 'pageID'";}?&When attempting to display the homepage using a pid of zero the above code will fail.So as a result i wrote a small function to replace the php empty() function in situations where you want 0 and "0" not to be considered empty.&?phpfunction is_empty($var, $allow_false = false, $allow_ws = false) {& & if (!isset($var) || is_null($var) || ($allow_ws == false && trim($var) == "" && !is_bool($var)) || ($allow_false === false && is_bool($var) && $var === false) || (is_array($var) && empty($var))) {& & & & & & return true;& & } else {& & & & return false;& & }}?&This function will allow you to test a variable is empty and considers the following values as empty:an unset variable -& emptynull -& empty0 -& NOT empty"0" -& NOT emptyfalse -& emptytrue -& NOT empty'string value' -& NOT empty"& & " (white space) -& emptyarray() (empty array) -& emptyThere are two optional parameters:$allow_false: setting this to true will make the function consider a boolean value of false as NOT empty. This parameter is false by default.$allow_ws: setting this to true will make the function consider a string with nothing but white space as NOT empty. This parameter is false by default.In Testing:&?phpecho 'unset variable ($notset) - Empty: ';echo is_empty($notset) ? 'yes&br /&' : 'no&br /&';echo 'null - Empty: ';$var = null;echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo '0 - Empty: ';$var = 0;echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo 'string "0" - Empty: ';$var = "0";echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo 'false - Empty: ';$var = false;echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo 'false ($allow_false = true) - Empty: ';$var = false;echo is_empty($var, true) ? 'yes&br /&' : 'no&br /&';echo 'true - Empty: ';$var = true;echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo 'string "foo" - Empty: ';$var = "foo";echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo 'white space "& && " - Empty: ';$var = "& & ";echo is_empty($var) ? 'yes&br /&' : 'no&br /&';echo 'white space ($allow_ws = true) "& && " - Empty: ';$var = "& & ";echo is_empty($var, false, true) ? 'yes&br /&' : 'no&br /&';echo 'empty array - Empty: ';$var = array();echo is_empty($var) ? 'yes&br /&' : 'no&br /&';?&the above code outputs the following:unset variable ($notset) - Empty: yesnull - Empty: yes0 - Empty: nostring "0" - Empty: nofalse - Empty: yesfalse ($allow_false = true) - Empty: notrue - Empty: nostring "foo" - Empty: nowhite space " " - Empty: yeswhite space ($allow_ws = true) " " - Empty: noempty array - Empty: yesHope this code is useful for someone.Michael
Note the exceptions when it comes to decimal numbers:&?php$a = 0.00;$b = '0.00';echo (empty($a)? "empty": "not empty"); echo (empty($b)? "empty": "not empty"); $c = intval($b);echo (empty($c)? "empty": "not empty"); ?&For those of you using MySQL, if you have a table with a column of decimal type, when you do a SELECT, your data will be returned as a string, so you'll need to do apply intval() before testing for empty.e.g.TABLE t has columns id MEDIUMINT and d DECIMAL(4,2)and contains 1 row where id=1, d=0.00&?php$q = "SELECT * FROM t";$res = mysql_query($q);$row = mysql_fetch_assoc($res);echo (empty($row['d'])? "empty": "not empty"); ?&
Add a empty recursivefunction is_empty($field) {& & return array_reduce($field, function($acc, $value){& & & & if ($acc === false) {& & & & & && & & & }& & & & & & & & return (is_array($value)) ? is_empty($value) : empty($value);& & });}
&?php$testCase = array(& & 1 =& '',& & 2 =& "",& & 3 =& null,& & 4 =& array(),& & 5 =& FALSE,& & 6 =& NULL,& & 7=&'0',& & 8=&0,& & );foreach ($testCase as $k =& $v) {& & if (empty($v)) {& & & & echo "&br& $k=&$v is empty";& & }}?&
Checking if a variable is empty or not when you have more than one will add so many simila and will require re-writing of course. L&?phpif (!empty($a))& & $myvar = $a;elseif (!empty($b))& && $myvar = $b;?&If, for example $myvar should be pulled among 5 vars, you need to write it for 5 times. But in the below example, using $myvar = esor($var1, $var2, ...) will set it to first non-empty var.&?phpfunction esor(){& & $arg_num = func_num_args();& & if (!$arg_num) return '';& & $args = func_get_args();& & for ($i = 0; $i & $arg_num; $i++)& & & & if (!empty($args[$i]))& & & & & & return $args[$i];& & return ''; }mail(esor($settings['admin_mail'], $_ENV['SERVER_ADMIN']), 'Something went wrong', 'Error was foo');?&This will make it "one line code" no matter how many vars you have to check. Hope that helps.
XML::Unserializer produces unexpected results because empty($key) is true when $key = 0.Example:&?phpinclude("/usr/share/php/XML/Unserializer.php");$xml= &&&EOD&?xml version="1.0"?&&groups _type="array"&& & &XML_Serializer_Tag _originalKey="0" _type="array"&& & & & &gid _type="integer"&10&/gid&& & &/XML_Serializer_Tag&& & &XML_Serializer_Tag _originalKey="5" _type="array"&& & & & &gid _type="integer"&100&/gid&& & &/XML_Serializer_Tag&&/groups&EOD;$uns = new XML_Unserializer();$res = $uns-&unserialize($xml);$recs = $uns-&getUnserializedData();print_r($recs);?&producesArray(& & [0] =& Array& & & & (& & & & & & [gid] =& 10& & & & )& & [5] =& Array& & & & (& & & & & & [gid] =& 100& & & & ))while&?phpinclude("/usr/share/php/XML/Unserializer.php");$xml= &&&EOD&?xml version="1.0"?&&groups _type="array"&& & &XML_Serializer_Tag _originalKey="5" _type="array"&& & & & &gid _type="integer"&100&/gid&& & &/XML_Serializer_Tag&& & &XML_Serializer_Tag _originalKey="0" _type="array"&& & & & &gid _type="integer"&10&/gid&& & &/XML_Serializer_Tag&&/groups&EOD;$uns = new XML_Unserializer();$res = $uns-&unserialize($xml);$recs = $uns-&getUnserializedData();print_r($recs);?&producesArray(& & [1] =& Array& & & & (& & & & & & [gid] =& 100& & & & )& & [6] =& Array& & & & (& & & & & & [gid] =& 10& & & & ))This is because the "empty" key value of 0 results in a push onto the end of the array, rather than an insertion at key position 0.
Re: inerte is
username's comment:While that may be true, those two statements (empty($var), $var == '') are NOT the same. When programming for web interfaces, where a user may be submitting '0' as a valid field value, you should not be using empty().&?php& & $str = '0';& & echo empty($str) ? 'empty' : 'not empty';& & echo $str == '' ? 'empty' : 'not empty';?&
David from CodeXplorer:&& The ONLY reason to use empty() is for code readability. It is the same as an IF/ELSE check.&& So, don't bother using EMPTY in the real world.This is NOT true.& empty() will not generate warnings if you're testing against an undefined variable as a simple boolean check will.& On production systems, warnings are usually shut off, but they are often active on development systems.You could test a flag with&& &?php if ($flagvar)& ... ?&but this can generate a warning if $flagvar is not set.Instead of && &?php if (isset($flagvar) && $flagvar)& ... ?&you can simply use&& &?php if (!empty($flagvar))& ... ?&for easy readability without warnings.
When using empty() on an object variable that is provided by the __get function, empty() will always return true.
For example:
&?php
class foo {
&&
&& public function __get($var) {
& & & if ($var == "bar") {
& & & && return "bar";&&
}
$object_foo = new foo();
echo '$object_foo-&bar is ' . $object_foo-&bar;
if (empty($object_foo-&bar)) {
&& echo '$object_foo-&bar seems to be empty';&&
produces the following output:
$object_foo-&bar is bar
$object_foo-&bar seems to be empty
in cases when "0" is not intended to be empty, here is a simple function to safely test for an empty string (or mixed variable):
&?php
function _empty($string){
& && $string = trim($string);
& && if(!is_numeric($string)) return empty($string);
& && return FALSE;
}
?&
Also, it doesn't appear to mention in the documentation, if a variable hasn't previously been declared, empty also returns true.E.g.var $empty( $bar ); // declared variable returns true.empty( $foo ); // undeclared variable also returns true.The closest the documentation comes to saying this is:"var $ (a variable declared, but without a value in a class)"which isn't really the same, as the variable doesn't necessarily have to be declared first.
Also note, that if you have a URI that looks like this:/page/index.php?query=performing isset($_GET['query']) will return TRUE. as query is set, though null, in the QUERY.To counteract this behavior, check isset($_GET['query']) and !empty($_GET['query']) as empty will detect the null value.
Since a few people here mentioned that empty will not work with magic-overloading ("__get($var)"): empty(..) goes the same way as isset(..) do, to check if a property exists. Thus you have to override the magic-function __isset($var) to produce correct results for empty(..) in combination with a magic-overloaded property.
In addiction to Ed comment:if an instance variable is assigned with an empty value, i.e. false, empty returns true.&?phpclass TestEmpty{& & protected& & & & && $empty;& & public& function& & __construct(){& & & & var_dump(empty($this-&empty)); $this-&empty = false;& & & & var_dump(empty($this-&empty)); }}new TestEmpty;?&I think this is an expected behaviour but at the same time the note about classes variables is too ambiguous.''var $ (a variable declared, but without a value in a class)''Please change them into something like:''var $ (a variable undeclared or declared with an empty value in a class)''
Hi you can check the status of multiple array or any variable is empty with below code.&?php$microtimeref = microtime ( true );$variable = array (array (0) );echo '&pre&';function getArray($dizi) {& & foreach ( $dizi as $value )& & & & return $value;}function isEmpty($array) {& & if (is_array ( $array )) {& & & & $dizi = getArray ( $array );& & & & if (is_array ( $dizi ))& & & & & & $ref = isEmpty ( $dizi );& & & & else & & & & & & if (strlen ( $dizi ) &= 1)& & & & & & & & return false;& & & & & & else& & & & & & & & return true;& & }& & else& & & & if (strlen ( $array ) &= 1)& & & & & & return false;& & & & else& & & & & & return true;& & & & if ($ref === false)& & & & return false;& & else& & & & return true;}$sonuc = isEmpty ( $variable );var_dump ( $sonuc );echo "Total time: &b&" . round ( microtime ( true ) - $microtimeref, 4 ) . 's&/b&&br /&';echo '&/pre&';?&Response:bool(false)& // not emptyTotal time: 0s
There's a faster and easier to write method than (isset($a) && strlen($a)) -- isset($a{0}). It evaluates to false if $a is not set or if it has zero length (ie. it's first character is not set). My tests indicate that it's about 33% faster.
Mad Hampster did& his test wrong. empty is NOT faster than a simple boolean check. The ONLY reason to use empty() is for code readability. It is the same as an IF/ELSE check. But if you are dealing with intermediate or higher level coders this function has no other benefit.So, don't bother using EMPTY in the real world.I ran an array with 5000 simple true/false values through four checks (both types twice) in case of any gain one type might have by going first. These are my results generated one one page request. (PHP5)0.015328 Time EMPTY0.014281 Time IF/ELSE0.015239 Time EMPTY0.013404 Time IF/ELSEThe page was accessed a couple times to reduce caching effects.
SAME RESULT! But somehow using empty() function is faster for about 10-13%&?php$array[] = "";$array[] = '';$array[] = 0;$array[] = "0";$array[] = NULL;$array[] = false;$array[] = array();$array[] = $var;foreach($array as $value){& & echo (!empty($value))? 'Not empty!' : 'Empty!';& & echo '&br /&'."\r\n";}echo '&br /&'."\r\n";foreach($array as $value){& & echo ($value)? 'Not empty!' : 'Empty!';& & echo '&br /&'."\r\n";}?&
function _empty() {
& & foreach(func_get_args() as $args) {
& & & & if( !is_numeric($args) ) {
& & & & & & if( is_array($args) ) { if( count($args, 1) & 1 ) return true;
& & & & & & }
& & & & & & elseif(!isset($args) || strlen(trim($args)) == 0)
& & & & & & & & return true;
& & & & & & }
& & & & }
& & }
& & return false;
}
Since this special case is not mentioned already: the empty() check does not work for mysqli resources / connections stored within a private variable. Instead ofif(!empty($this-&dbConn-&error)){...}you have to use$error = $this-&dbConn-& if(!empty($error)){...}otherwise the condition will not evaluate to true in case a mysqli error is given for the present connection.