in_array

(PHP 4, PHP 5, PHP 7)

in_arrayBir dizide bir değerin varlığını araştırır

Açıklama

in_array ( mixed $iğne , array $samanlık [, bool $strict ] ) : bool

samanlık'ta iğne'yi' arar.

Değiştirgeler

iğne

Aranan değer.

Bilginize:

iğne bir dizge ise harf büyüklüğüne duyarlı karşılaştırma uygulanır.

samanlık

Dizi.

türüne_de_bak

Bu değiştirgede TRUE belirtilmişse in_array() işlevi samanlık içindeki iğne'nin türüne de bakacaktır.

Dönen Değerler

iğne bulunursa TRUE, aksi takdirde FALSE döner.

Sürüm Bilgisi

Sürüm: Açıklama
4.2.0 iğne olarak bir dizi belirtilebilir oldu.

Örnekler

Örnek 1 - in_array() örneği

<?php
$os 
= array("Mac""NT""Irix""Linux");
if (
in_array("Irix"$os)) {
    echo 
"Irix var";
}
if (
in_array("mac"$os)) {
    echo 
"Mac var";
}
?>

The second condition fails because in_array() işlevi harf büyüklüğüne duyarlı olduğundan ikinci koşul başarısız olur ve sonuç şu olur:

Irix var

Örnek 2 - Türe de bakan in_array() örneği

<?php
$a 
= array('1.10'12.41.13);

if (
in_array('12.4'$atrue)) {
    echo 
"'12.4' uygun türde bulundu\n";
}

if (
in_array(1.13$atrue)) {
    echo 
"1.13 uygun türde bulundu\n";
}
?>

Yukarıdaki örneğin çıktısı:

1.13 uygun türde bulundu

Örnek 3 - iğnenin bir dizi olduğu in_array() örneği

<?php
$a 
= array(array('p''h'), array('p''r'), 'o');

if (
in_array(array('p''h'), $a)) {
    echo 
"'ph' bulundu\n";
}

if (
in_array(array('f''i'), $a)) {
    echo 
"'fi' bulundu\n";
}

if (
in_array('o'$a)) {
    echo 
"'o' bulundu\n";
}
?>

Yukarıdaki örneğin çıktısı:

  'ph' bulundu
  'o' bulundu

Ayrıca Bakınız

  • array_search() - Bir dizide belirtilen değeri arar ve bulursa ilgili anahtarı döndürür
  • isset() - Değişken tanımlı mı diye bakar
  • array_key_exists() - Belirtilen anahtar veya indis dizide var mı diye bakar

add a note add a note

User Contributed Notes 35 notes

up
310
beingmrkenny at gmail dot com
8 years ago
Loose checking returns some crazy, counter-intuitive results when used with certain arrays. It is completely correct behaviour, due to PHP's leniency on variable types, but in "real-life" is almost useless.

The solution is to use the strict checking option.

<?php

// Example array

$array = array(
   
'egg' => true,
   
'cheese' => false,
   
'hair' => 765,
   
'goblins' => null,
   
'ogres' => 'no ogres allowed in this array'
);

// Loose checking -- return values are in comments

// First three make sense, last four do not

in_array(null, $array); // true
in_array(false, $array); // true
in_array(765, $array); // true
in_array(763, $array); // true
in_array('egg', $array); // true
in_array('hhh', $array); // true
in_array(array(), $array); // true

// Strict checking

in_array(null, $array, true); // true
in_array(false, $array, true); // true
in_array(765, $array, true); // true
in_array(763, $array, true); // false
in_array('egg', $array, true); // false
in_array('hhh', $array, true); // false
in_array(array(), $array, true); // false

?>
up
10
Camille Dugas
1 month ago
<?php

class Method {

   
/** @var int current number of inMultiArray() loop */
   
private static $currentMultiArrayExec = 0;

   
/**
     * Checks if an element is found in an array or one of its subarray.
     * The verification layer of this method is limited to the parameter boundary xdebug.max_nesting_level of your php.ini.
     * @param mixed $element
     * @param array $array
     * @param bool $strict
     * @return bool
     */
   
public static function inMultiArray($element, array $array, bool $strict = true) : bool {
       
self::$currentMultiArrayExec++;

        if(
self::$currentMultiArrayExec >= ini_get("xdebug.max_nesting_level")) return false;

        foreach(
$array as $key => $value){
           
$bool = $strict ? $element === $key : $element == $key;

            if(
$bool) return true;

            if(
is_array($value)){
               
$bool = self::inMultiArray($element, $value, $strict);
            } else {
               
$bool = $strict ? $element === $value : $element == $value;
            }

            if(
$bool) return true;
        }

       
self::$currentMultiArrayExec = 0;
        return isset(
$bool) ? $bool : false;
    }
}

$array = array("foo" => array("foo2", "bar"));
$search = "foo";

if(
Method::inMultiArray($search, $array, false)){
    echo
$search . " it is found in the array or one of its sub array.";
} else {
    echo
$search . " was not found.";
}

# foo it is found in the array or one of its sub array.
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4
artem dot g dot prozorov at gmail dot com
3 months ago
in_array() may also return NULL if the second argument is NULL and strict types are off.

<?php
var_dump
(in_array(1, null));
?>

The output is NULL

If the strict mode is on, then this code would end up with the TypeError
up
132
jv at vip dot ie
9 years ago
If you're working with very large 2 dimensional arrays (eg 20,000+ elements) it's much faster to do this...

<?php
$needle
= 'test for this';

$flipped_haystack = array_flip($haystack);

if ( isset(
$flipped_haystack[$needle]) )
{
  print
"Yes it's there!";
}
?>

I had a script that went from 30+ seconds down to 2 seconds (when hunting through a 50,000 element array 50,000 times).

Remember to only flip it once at the beginning of your code though!
up
68
Kelvin J
10 years ago
For a case-insensitive in_array(), you can use array_map() to avoid a foreach statement, e.g.:

<?php
   
function in_arrayi($needle, $haystack) {
        return
in_array(strtolower($needle), array_map('strtolower', $haystack));
    }
?>
up
23
Lea Hayes
8 years ago
Determine whether an object field matches needle.

Usage Example:
---------------

<?php
$arr
= array( new stdClass(), new stdClass() );
$arr[0]->colour = 'red';
$arr[1]->colour = 'green';
$arr[1]->state  = 'enabled';

if (
in_array_field('red', 'colour', $arr))
   echo
'Item exists with colour red.';
if (
in_array_field('magenta', 'colour', $arr))
   echo
'Item exists with colour magenta.';
if (
in_array_field('enabled', 'state', $arr))
   echo
'Item exists with enabled state.';
?>

Output:
--------
Item exists with colour red.
Item exists with enabled state.

<?php
function in_array_field($needle, $needle_field, $haystack, $strict = false) {
    if (
$strict) {
        foreach (
$haystack as $item)
            if (isset(
$item->$needle_field) && $item->$needle_field === $needle)
                return
true;
    }
    else {
        foreach (
$haystack as $item)
            if (isset(
$item->$needle_field) && $item->$needle_field == $needle)
                return
true;
    }
    return
false;
}
?>
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4
rhuan at rhuan dot com dot br
2 years ago
This code will search for a value in a multidimensional array with strings or numbers on keys.

function in_multiarray($elem, $array)
{
    while (current($array) !== false) {
        if (current($array) == $elem) {
            return true;
        } elseif (is_array(current($array))) {
            if (in_multiarray($elem, current($array))) {
                return true;
            }
        }
        next($array);
    }
    return false;
}
up
18
bogdan AT bogdanconstantinescu DOT com
9 years ago
If you found yourself in need of a multidimensional array in_array like function you can use the one below. Works in a fair amount of time

<?php

   
function in_multiarray($elem, $array)
    {
       
$top = sizeof($array) - 1;
       
$bottom = 0;
        while(
$bottom <= $top)
        {
            if(
$array[$bottom] == $elem)
                return
true;
            else
                if(
is_array($array[$bottom]))
                    if(
in_multiarray($elem, ($array[$bottom])))
                        return
true;
                   
           
$bottom++;
        }       
        return
false;
    }
?>
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6
what loose checking means
5 years ago
In a high-voted example, an array is given that contains, amongst other things, true, false and null, against which various variables are tested using in_array and loose checking.

It impossible to receive false as a return value from in_array using loose checking if your arrays contains both the constants true and false. You might understandably trip over this (or the inverse - passing boolean true to check against an array of e.g. non-empty strings), but it's certainly not counter intuitive and makes perfect sense.
up
6
ctulek at gmail dot com
9 years ago
If you have an array like:
$arr = array(0,1,2,3,4,5);

in_array(NULL, $arr) returns true because you have 0 in your array. That is, in_array does not use === for equal check.
up
4
janis dot janovskis at gmail dot com
7 years ago
Since sometimes in_array returns strange results - see notes above.
I was able to find value in array by this quite a simple function;
<?php
/**
* $find <mixed> value to find
* $array<array> array to search in
*/

function _value_in_array($array, $find){
$exists = FALSE;
if(!
is_array($array)){
   return;
}
foreach (
$array as $key => $value) {
  if(
$find == $value){
      
$exists = TRUE;
  }
}
  return
$exists;
}

// Note
// You can't use wildcards and it does not check variable type
?>
up
1
dazero0 dot ls at gmail dot com
4 years ago
I would like to add something to beingmrkenny at gmail dot com comparison post. After debugging a system, i discovered a security issue in our system and his post helped me find the problem.

In my additional testing i found out that not matter what you search for in an array, except for 0 and null, you get true as the result if the array contains true as the value.

Examples as php code :

<?php
$a
= ['a', 32, true, 'x' => y];
var_dump(in_array(25, $a)); // true, one would expect false
var_dump(in_array('ggg', $a)); // true, one would expect false

var_dump(in_array(0, $a)); // false
var_dump(in_array(null, $a)); // false
?>

Such the best practice in our case is to use strict mode. Which was not so obvious.
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3
crashrox at gmail dot com
11 years ago
Recursive in array using SPL

<?php
function in_array_recursive($needle, $haystack) {

   
$it = new RecursiveIteratorIterator(new RecursiveArrayIterator($haystack));

    foreach(
$it AS $element) {
        if(
$element == $needle) {
            return
true;
        }
    }

    return
false;
}
?>
up
2
Valerchik
6 years ago
Beware when using this function to validate user input:

$a = array('0' => 'Opt 1', '1' => 'Opt 2', '2' => 'Opt 3');
$v = 'sql injection';
var_dump(in_array($v, array_keys($a)));

This will result : true;

array_keys($a) will cast array keys to int instead of string !
then when in_array will compare it will cast  'sql injection' to int 0 !
Beware of this!
up
2
rhill at xenu-directory dot net
10 years ago
I found out that in_array will *not* find an associative array within a haystack of associative arrays in strict mode if the keys were not generated in the *same order*:

<?php

$needle
= array(
   
'fruit'=>'banana', 'vegetable'=>'carrot'
   
);

$haystack = array(
    array(
'vegetable'=>'carrot', 'fruit'=>'banana'),
    array(
'fruit'=>'apple', 'vegetable'=>'celery')
    );

echo
in_array($needle, $haystack, true) ? 'true' : 'false';
// Output is 'false'

echo in_array($needle, $haystack) ? 'true' : 'false';
// Output is 'true'

?>

I had wrongly assumed the order of the items in an associative array were irrelevant, regardless of whether 'strict' is TRUE or FALSE: The order is irrelevant *only* if not in strict mode.
up
2
thomas dot sahlin at gmail dot com
10 years ago
If you're creating an array yourself and then using in_array to search it, consider setting the keys of the array and using isset instead since it's much faster.

<?php

$slow
= array('apple', 'banana', 'orange');

if (
in_array('banana', $slow))
    print(
'Found it!');

$fast = array('apple' => 'apple', 'banana' => 'banana', 'orange' => 'orange');

if (isset(
$fast['banana']))
    print(
'Found it!');

?>
up
-1
loordu
2 months ago
In PHP array function the in_array() function mainly used to check the item are available or not in array.

In_array() Syntax:

in_array( 'search_item' , $array, boolean)

Where,
     boolean - It is used to check strict validation. And this field is optional one. If you want the strict validation you can use this.

We using in_array() function to performing following following two function. That is ,

1. Non-strict validation
2. Strict validation

1. Non-strict validation:
     This method to validate array with some negotiation. And it allow two parameters.

     For example,
          $array_sample = array (  'key1' => 567 , 'key2' => 579);

          in_array('key1', $array_sample);   // output1:  true
          in_array('577', $array_sample, false);   // output2:  true

      Note: the Example 1, we use only two parameter. Because we can't mention `false` value. Because In default the in_array() take `false` as a boolean value.

      In above example,
             Example 1 : The `key1` is not value in the array.    This is key of the array. So this scenario the in_array accept the search key as a value of the array.
             Example 2: The value `577` is not in the value and key of the array. It is some similar to the value `579`. So this is also accepted.

     So this reason this type is called non-strict function.

2. Strict validation
     This method to validate array without any negotiation. And it have three parameters. If you only mention two parameter the `in_array()` function take as a non-strict validation.

     For example,
          $array_sample = array (  'key1' => 567 , 'key2' => 579);

          in_array('key1', $array_sample , true);   // output1:  false
          in_array('577', $array_sample, true);   // output2:  false
       
    This is return `true` only the search string is match exactly with the array value with case sensitivity.

Thanks for your time.
up
1
rolf dot dergham dot public at gmail dot com
5 years ago
Watch out for this:

<?

print_r( (int) in_array('hello',array( 0 => 0)) );

?>

returns 1

Yes, it seems that is_array thinks that a random string and 0 are the same thing.
Excuse me, that's not loose checking, that's drunken logic.
Or maybe I found a bug?
up
-1
iammanjil at gmail dot com
1 year ago
If third parameter is not set to Strict then, the needle is found in haystack eventhought the values are not same. the limit behind the decimal seems to be 6 after which, the haystack and needle match no matter what is behind the 6th.

Wrong Response.
$os = array("652875063.10089021");
if (in_array("652875063.10089021", $os)) {
    echo "In Array";
}

Correct Response
$os = array("652875063.1008902");
if (in_array("652875063.1008901", $os)) {
    echo "In Array";
}
up
0
Carmen
1 year ago
Esta función falla con las letras acentuadas y con las eñes. Por tanto, no sirve para los caracteres UTF-8.
El siguiente código falla para na cadena = "María Mañas", no reconoce ni la "í" ni la "ñ":

    function validarNombreYApellidos ($cadena, $selector)
    {
        /* Se admiten las letras (he puesto sólo las mayusculas,
             porque paso la cadena con el nombre o
             el apellido a mayúscula antes de hacer la comparación),
             las vocales acentuadas, la diéresis,
             las eñes, los espacios en blanco y el guión
            (para los apellidos compuestos)*/
        $caracteresPermitidos =
               array ("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
                          "N", "Ñ", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X",
                          "Y",  "Z", " ", "Á", "É", "Í", "Ó", "Ú", "Ü", "-");
       
        $correcto = true;

        // ¿La cadena está vacía?
        if (empty ($cadena))
        {
            $correcto = false;
        }
        else
        {
            $nombreOapellido = mb_strtoupper ($cadena, "utf-8");
            $longitudCadena = mb_strlen ($cadena, "utf-8");

            for ($i = 0; ($i < $longitudCadena) && $correcto; $i++)
            {
                if (!in_array ($nombreOapellido [$i],
                                     $caracteresPermitidos))
                {
                    // Se ha encontrado un carácter no permitido
                    $correcto = false;
                }
            }
        }
            return $correcto;
     }
up
0
Carmen
1 year ago
Esta función falla con las letras acentuadas y con las eñes. Por tanto, no sirve para los caracteres UTF-8.
El siguiente código falla para na cadena = "María Mañas", no reconoce ni la "í" ni la "ñ":

    function validarNombreYApellidos ($cadena, $selector)
    {
        /* Se admiten las letras (he puesto sólo las mayusculas,
             porque paso la cadena con el nombre o
             el apellido a mayúscula antes de hacer la comparación),
             las vocales acentuadas, la diéresis,
             las eñes, los espacios en blanco y el guión
            (para los apellidos compuestos)*/
        $caracteresPermitidos =
               array ("A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",
                          "N", "Ñ", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X",
                          "Y",  "Z", " ", "Á", "É", "Í", "Ó", "Ú", "Ü", "-");
       
        $correcto = true;

        // ¿La cadena está vacía?
        if (empty ($cadena))
        {
            $correcto = false;
        }
        else
        {
            $nombreOapellido = mb_strtoupper ($cadena, "utf-8");
            $longitudCadena = mb_strlen ($cadena, "utf-8");

            for ($i = 0; ($i < $longitudCadena) && $correcto; $i++)
            {
                if (!in_array ($nombreOapellido [$i],
                                     $caracteresPermitidos))
                {
                    // Se ha encontrado un carácter no permitido
                    $correcto = false;
                }
            }
        }
            return $correcto;
     }
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1
john at dwarven dot co dot uk
10 years ago
I just struggled for a while with this, although it may be obvious to others.

If you have an array with mixed type content such as:

<?php

$ary
= array (
  
1,
  
"John",
  
0,
  
"Foo",
  
"Bar"
);

?>

be sure to use the strict checking when searching for a string in the array, or it will match on the 0 int in that array and give a true for all values of needle that are strings strings.

<?php

var_dump
( in_array( 2, $ary ) );

// outputs FALSE

var_dump( in_array( 'Not in there', $ary ) );

// outputs TRUE

var_dump( in_array( 'Not in there', $ary, TRUE ) );

// outputs FALSE

?>
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1
adrian foeder
14 years ago
hope this function may be useful to you, it checks an array recursively (if an array has sub-array-levels) and also the keys, if wanted:

<?php
function rec_in_array($needle, $haystack, $alsokeys=false)
    {
        if(!
is_array($haystack)) return false;
        if(
in_array($needle, $haystack) || ($alsokeys && in_array($needle, array_keys($haystack)) )) return true;
        else {
            foreach(
$haystack AS $element) {
               
$ret = rec_in_array($needle, $element, $alsokeys);
            }
        }
       
        return
$ret;
    }
?>
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0
stocki dot r at gmail dot com
2 years ago
Add an extra if() to adrian foeder's comment to make it work properly:

<?php
   
...
    if (!@
$ret) {
       
$ret = rec_in_array($needle, $element, $alsokeys);
    }
    ...
?>

So this will work, too:

<?php
    $array
= array(
        array(
'a', 'b'),
        array(
'c', 'd')
    );
   
var_dump(rec_in_array('a', $array));
?>
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-2
msegit post pl
1 year ago
You can use my function inArray, to search:
- multidimensional arrays
- for substrings (case [in]sensitive)
- for sub-arrays
- get array of keys of found values
Look at github https://gist.github.com/msegu/80093a65316ded5b69558d5456f80ff9 (here is too long)
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1
sick949 at hotmail dot com
11 years ago
A first idea for a function that checks if a text is in a specific column of an array.
It does not use in_array function because it doesn't check via columns.
Its a test, could be much better. Do not use it without test.

<?php

function in_array_column($text, $column, $array)
{
    if (!empty(
$array) && is_array($array))
    {
        for (
$i=0; $i < count($array); $i++)
        {
            if (
$array[$i][$column]==$text || strcmp($array[$i][$column],$text)==0) return true;
        }
    }
    return
false;
}

?>
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1
Martijn Wieringa
11 years ago
When using numbers as needle, it gets tricky:

Note this behaviour (3rd statement):

in_array(0, array(42)) = FALSE
in_array(0, array('42')) = FALSE
in_array(0, array('Foo')) = TRUE
in_array('0', array('Foo')) = FALSE
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-1
hoopyfroop at yahoo dot com
3 years ago
If you search for numbers, in_array will convert any strings in your array to numbers, dropping any letters/characters, forcing a numbers-to-numbers comparison. So if you search for 1234, it will say that '1234abcd' is a match.  Example:

<?php
$test_array
= array('test', '1234abcd');
if (
in_array(1234, $test_array)) {
    echo
'1234 is a match!';
}
?>
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0
Aragorn5551 at gmx dot de
14 years ago
If you have a multidimensional array filled only with Boolean values like me, you need to use 'strict', otherwise in_array() will return an unexpected result.

Example:

<?php
$error_arr
= array('error_one' => FALSE, 'error_two' => FALSE, array('error_three' => FALSE, 'error_four' => FALSE));

if (
in_array (TRUE, $error_arr)) {
   echo
'An error occurred';
}
else {
   echo
'No error occurred';
}
?>

This will return 'An error occurred' although theres no TRUE value inside the array in any dimension. With 'strict' the function will return the correct result 'No error occurred'.

Hope this helps somebody, cause it took me some time to figure this out.
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-1
splogamurugan at gmail dot com
4 years ago
var_dump(in_array('invalid', array(0,10,20)));
The above code gives true since the 'invalid' is getting converted to 0 and checked against the array(0,10,20)

but var_dump(in_array('invalid', array(10,20)));  gives 'false' since 0 not there in the array
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-1
Geoffrey Hoffman
2 years ago
Be careful to use the strict parameter with truth comparisons of specific strings like "false":

<?php

$truthy
= [true, 'true', 1, '1', 'y', 'Y', 'yes', 'YES'];

if (
in_array('false', $truthy)) {
   echo
"False is truthy.\n";
} else {
   echo
"False is not truthy.\n";
}

if (
in_array('false', $truthy, true)) {
    echo
"False is truthy.\n";
} else {
    echo
"False is not truthy.\n";
}

?>

The above example prints:

False is truthy.
False is not truthy.
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-1
tjamadeira at gmail dot com
3 years ago
This function is for search a needle in a multidimensional haystack:

<?php
/**
* A special function for search in a multidimensional array a needle
*
* @param mixed needle The searched variable
* @param array haystack The array where search
* @param bool strict It is or it isn't a strict search?
*
* @return bool
**/
function in_array_r($needle, $haystack, $strict = false){
foreach(
$haystack as $item){
   if(
is_array($item)){
     if(
in_array_r($needle, $item, $strict)){
       return
true;
     }
   }else{
     if((
$strict ? $needle === $item : $needle == $item)){
       return
true;
     }
   }
}
return
false;
}
?>
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-1
musik at krapplack dot de
13 years ago
I needed a version of in_array() that supports wildcards in the haystack. Here it is:

<?php
function my_inArray($needle, $haystack) {
   
# this function allows wildcards in the array to be searched
   
foreach ($haystack as $value) {
        if (
true === fnmatch($value, $needle)) {
            return
true;
        }
    }
    return
false;
}

$haystack = array('*krapplack.de');
$needle = 'www.krapplack.de';

echo
my_inArray($needle, $haystack); # outputs "true"
?>

Unfortunately, fnmatch() is not available on Windows or other non-POSIX compliant systems.

Cheers,
Thomas
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-1
roman dot varuta at gmail dot com
1 year ago
If array contain at least one true value, in_array() will return true every times if it is not false or null

Use strict = true

<?php

$arr
= array(true);

in_array($any, $arr); // Will return true every time except null and false

?>
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-4
Harry Willis
4 years ago
Kelvin's case-insensitive in_arrayi is fine if you desire loose typing, but mapping strtolower onto the array will (attempt to) cast all array members to string. If you have an array of mixed types, and you wish to preserve the typing, the following will work:

<?php
function in_array_ci($needle, array $haystack, $strict = false) {
    foreach (
$haystack as $element) {
        if (
gettype($needle) == 'string' && gettype($element) == 'string') {
            if (!
strcasecmp($needle, $element)) {
                return
true;
            }
        }
        elseif (
$strict) {
            if (
$needle === $element) {
                return
true;
            }
        }
        else {
            if (
$needle == $element) {
                return
true;
            }
        }
    }

    return
false;
}
?>
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