Как проверить пустой массив или нет php

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How to Check Whether an Array Is Empty in PHP

Sometimes a software crash or other unexpected circumstances can occur because of an empty array. Hence, it is crucial to detect empty arrays beforehand and avoid them. This tutorial represents how to inspect whether a particular array is empty or not in PHP.

Let’s check out several useful means that will help you meet that goal.

Applying the empty() Function

The first method is applying the empty() function as shown in the example below:

The output of this code will indicate that the array is empty.

Applying the count() Function

The next function to use for detecting an empty array is the count() function. This function differs from the one above: it is aimed at counting the elements inside an array.

This function returns 0 once the array is empty. Otherwise, the number of elements will be returned. In the case below, the result is 0. Thus, the given array is empty:

Now, let’s see another example where the number of the elements is returned:

The output of this example is 4. It means that the array includes 4 elements.

Applying the sizeof() Function

The third method is using the sizeof() function. Globally, it is used for checking the array size. When its size is 0, then the array is considered empty. Otherwise, it’s not empty.

empty() | Check if an Array is Empty or Not in PHP

The simplest way to use Check if an Array is Empty or Not in PHP example looks like this.

Output :- Not Empty Array

Here, in this code define PHP check array with the using empty() function example and apply along with the condition. Also, implement this method on your source code of functionality. According, have to how another example in the below section with empty() function.

How to check if an array is empty – empty()

Now, display this example for using !empty() function. Firstly, Store an array of variables this is an index array then apply conditions to check array values are empty. The best example must apply anywhere on the page.

Hence, Keep scrolling down for the next chapter.

How to Push Associative Array in PHP

Usually, we give a basic example that how to push associative array in PHP, First, I have pushed a single key and value inside the associative array. After that, given some more examples like it multiple arrays pushing with the using PHP function.

So, this is the best simple example to add and push any type of array in your codes. Now, show you another example with the single key and value. check out the below section.

Array Push Multidimensional PHP

Hence, you can see until the concept to push of multidimensional array. Here, only created an array variable. Also, add on value in the same variable with the push other array key and value see this below.

array_push() function PHP Example

Here, provide a PHP function for the index array. Now, see how to insert a value inside the array with array_push() see below.

Output :- Array ( [0] => one [1] => two [2] => three [3] => four )

Hence, Keep scrolling down to the next example.

in_array() in PHP | Array Value Exists, Associative/Multidimensional

The in_array() example here. Basically array function searches any specific value from the array. Here, We provide in_array in PHP as well as added another example for array value exists with the help index array.

Also, share two examples of in_array associative array PHP and multidimensional. So, you can see the code in the below section.

Although, apply this example for index array and created a $arr variable defined array.

Also, inserted some string values then apply if condition to check array value exists or not in the array. As well As mention output condition.

in_array Associative Array PHP

Similarly, In this example, and in array function only searches values that exist then condition true and false.

So you can see below example have applied for associative array and check value exists with the using in_array().

in_array() Multidimensional

In this example, we applied for multidimensional arrays. Here, in this array, only one concept to searches value from the array.

Firstly, check the value that which array available value have mention array to array path by array values. and then find as this example display code.

Hence, Keep scrolling down to the next example.

is_array() | is Array PHP function With Example

Now, we give the best example of is array PHP and how to check an array is empty are not. As well as define what is_array() or how to use is_array() in PHP.

Output:- Available

Here, Also given another example of is_array(). So, in this example passing string in a variable that must pass is array function. It means out will be of else condition check it below code.

is Array PHP function Example — is_array()

Now output:- Not Available

Therefore, you can see this type out if you put this function is_array( $arr ). It means only give only boolean as true and false. Secondly, put this code anywhere with the condition and check that is an array or not. Also, Check this example empty()

Hence, Keep scrolling down to the next example.

strrev() | PHP Reverse String | Example

The simplest PHP Reverse String example looks like this.

Outputs — trams nrael bew

strrev() — How to Reverse a String

In this chapter, I added an example for the PHP reverse string. So, you can apply this example and reverse each word character as well as possibly change a string.

Hence, Keep scrolling down for the next chapter.

strlen() | String Length PHP | Example

The simplest string length PHP example looks like this.

Outputs — 23

strlen() — Count length of string in PHP

In this chapter, you can see PHP strlen function. accordingly, get the length of the string with this example. Also, you can apply conditions with the use of common syntax. Also read about more information Submit Form without Page Refresh using Ajax jQuery PHP

Keep scrolling down for the next chapter.

str_word_count() | Word limit in PHP | Example

The simplest way word limit in PHP example looks like this.

Outputs — 3

str_word_count() — Word count in PHP

In this chapter, you can see examples of a number of words in this string. Also, implement with the condition. Accordingly, you must apply and try this condition on your project for the string in PHP. How to Insert JSON data into MySQL using PHP

empty

Determine whether a variable is considered to be empty. A variable is considered empty if it does not exist or if its value equals false . empty() does not generate a warning if the variable does not exist.

Parameters

Variable to be checked

No warning is generated if the variable does not exist. That means empty() is essentially the concise equivalent to !isset($var) || $var == false.

Return Values

Returns true if var does not exist or has a value that is empty or equal to zero, aka falsey, see conversion to boolean. Otherwise returns false .

Examples

Example #1 A simple empty() / isset() comparison.

// Evaluates to true because $var is empty
if (empty( $var )) <
echo ‘$var is either 0, empty, or not set at all’ ;
>

// Evaluates as true because $var is set
if (isset( $var )) <
echo ‘$var is set even though it is empty’ ;
>
?>

Example #2 empty() on String Offsets

The above example will output:

Notes

Note: Because this is a language construct and not a function, it cannot be called using variable functions, or named arguments.

Note:

When using empty() on inaccessible object properties, the __isset() overloading method will be called, if declared.

User Contributed Notes 36 notes

<?php
/**
* @author : Nanhe Kumar <nanhe.kumar@gmail.com>
* List of all empty values
**/

foreach ( $testCase as $k => $v ) <
if (empty( $v )) <
echo «<br> $k => $v is empty» ;
>
>
/**
Output
1=> is empty
2=> is empty
3=> is empty
4=>Array is empty
5=> is empty
6=> is empty
7=>0 is empty
8=>0 is empty
**/
?>

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:

$registry = new Registry ();
$registry -> empty = » ;
$registry -> notEmpty = ‘not empty’ ;

var_dump (empty( $registry -> notExisting )); // true, so far so good
var_dump (empty( $registry -> empty )); // true, so far so good
var_dump (empty( $registry -> notEmpty )); // true, .. say what?
$tmp = $registry -> notEmpty ;
var_dump (empty( $tmp )); // false as expected
?>

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:

<?php
class 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 )); // true, so far so good
var_dump (empty( $registry -> empty )); // true, so far so good
var_dump (empty( $registry -> notEmpty )); // false, finally!
?>

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.

Multiple empty():
<?php
/**
* Multiple empty().
*
* @param mixed[] $vars Variables to test
* @return bool
*/
function multi_empty (& . $vars )
<
// no callback is supplied, all empty values will be removed
return array_filter ( $vars ) === [];
>
?>
example:
<?php
$notEmptyVar = 1 ;
$emptyVar = null ;
// $undefinedVar — not defined

multi_empty ( $emptyVar ); // true
multi_empty ( $emptyVar , $undefinedVar ); // true
multi_empty ( $notEmptyVar , $emptyVar ); // false
multi_empty ( $notEmptyVar , $emptyVar , $undefinedVar ); // false
?>

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)

<?php
function is_blank ( $value ) <
return empty( $value ) && ! is_numeric ( $value );
>
?>

This is similar to Rails’ blank? method.

(experienced in PHP 5.6.3) The `empty()` can’t evaluate `__get()` results explicitly, so the `empty()` statement bellow always renders true
<?php
class 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 output is:
* bool(true)
*/
?>

The correct way is to force the evaluation of `__get()` first, by using extra braces around implicit statements like this:
<?php
var_dump (empty(( $this -> liquid -> apple )));

/**
* The output is:
* bool(false)
*/
?>

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.

I normally count() an array, so I wanted to see how empty() would stack up.

<?php
$test = array();
$test2 = array();
for ( $x = 0 ; $x < 1000 ; $x ++) $test [] = $x ;

$ts = microtime ( true );
for ( $x = 0 ; $x < 100000000 ; $x ++)
<
if ( count ( $test ))
<
>
>

echo «Time taken: » . ( microtime ( true ) — $ts ) . » sec\n» ;
?>

For 100,000,000 comparisons, here are the results against PHP 7.2.16 on my hardware:

count($test): 2.697 sec
count($test2): 2.596 sec
$test === array(): 2.579 sec
$test2 === array(): 2.552 sec
empty($test): 3.085 sec
empty($test2): 3.113 sec

In short, it doesn’t matter what method is used although empty() is actually just ever so slightly slower despite it being a language construct. YMMV.

<?php
$str = ‘ ‘ ;
var_dump (empty( $str )); // boolean false
?>

So remember to trim your strings first!

<?php
$str = ‘ ‘ ;
$str = trim ( $str );
var_dump (empty( $str )); // boolean true
?>

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:

(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 converted
and
$a==$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.

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:
<?php
function is_empty ( $var ) <

return empty( $var );

>
?>
Then you can do something like
<?php
if( is_empty ( NULL )) <
/* . */
>
?>
without issue, since the local variable $var is being tested rather than the expression in the function call itself.

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 keyword»>. 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=

Как проверить пустой массив или нет php