in_array() and multidimensional array
PhpArraysMultidimensional ArrayPhp Problem Overview
I use in_array() to check whether a value exists in an array like below,
$a = array("Mac", "NT", "Irix", "Linux");
if (in_array("Irix", $a))
{
echo "Got Irix";
}
//print_r($a);
but what about an multidimensional array (below) - how can I check that value whether it exists in the multi-array?
$b = array(array("Mac", "NT"), array("Irix", "Linux"));
print_r($b);
or I shouldn't be using in_array() when comes to the multidimensional array?
Php Solutions
Solution 1 - Php
in_array() does not work on multidimensional arrays. You could write a recursive function to do that for you:
function in_array_r($needle, $haystack, $strict = false) {
foreach ($haystack as $item) {
if (($strict ? $item === $needle : $item == $needle) || (is_array($item) && in_array_r($needle, $item, $strict))) {
return true;
}
}
return false;
}
Usage:
$b = array(array("Mac", "NT"), array("Irix", "Linux"));
echo in_array_r("Irix", $b) ? 'found' : 'not found';
Solution 2 - Php
If you know which column to search against, you can use array_search() and array_column():
$userdb = Array
(
(0) => Array
(
('uid') => '100',
('name') => 'Sandra Shush',
('url') => 'urlof100'
),
(1) => Array
(
('uid') => '5465',
('name') => 'Stefanie Mcmohn',
('url') => 'urlof5465'
),
(2) => Array
(
('uid') => '40489',
('name') => 'Michael',
('url') => 'urlof40489'
)
);
if(array_search('urlof5465', array_column($userdb, 'url')) !== false) {
echo 'value is in multidim array';
}
else {
echo 'value is not in multidim array';
}
This idea is in the comments section for array_search() on the PHP manual;
Solution 3 - Php
This will work too.
function in_array_r($item , $array){
return preg_match('/"'.preg_quote($item, '/').'"/i' , json_encode($array));
}
Usage:
if(in_array_r($item , $array)){
// found!
}
Solution 4 - Php
This will do it:
foreach($b as $value)
{
if(in_array("Irix", $value, true))
{
echo "Got Irix";
}
}
in_array only operates on a one dimensional array, so you need to loop over each sub array and run in_array on each.
As others have noted, this will only for for a 2-dimensional array. If you have more nested arrays, a recursive version would be better. See the other answers for examples of that.
Solution 5 - Php
$userdb = Array
(
(0) => Array
(
('uid') => '100',
('name') => 'Sandra Shush',
('url') => 'urlof100'
),
(1) => Array
(
('uid') => '5465',
('name') => 'Stefanie Mcmohn',
('url') => 'urlof5465'
),
(2) => Array
(
('uid') => '40489',
('name') => 'Michael',
('url') => 'urlof40489'
)
);
$url_in_array = in_array('urlof5465', array_column($userdb, 'url'));
if($url_in_array) {
echo 'value is in multidim array';
}
else {
echo 'value is not in multidim array';
}
Solution 6 - Php
if your array like this
$array = array(
array("name" => "Robert", "Age" => "22", "Place" => "TN"),
array("name" => "Henry", "Age" => "21", "Place" => "TVL")
);
Use this
function in_multiarray($elem, $array,$field)
{
$top = sizeof($array) - 1;
$bottom = 0;
while($bottom <= $top)
{
if($array[$bottom][$field] == $elem)
return true;
else
if(is_array($array[$bottom][$field]))
if(in_multiarray($elem, ($array[$bottom][$field])))
return true;
$bottom++;
}
return false;
}
example : echo in_multiarray("22", $array,"Age");
Solution 7 - Php
For Multidimensional Children: in_array('needle', array_column($arr, 'key'))
For One Dimensional Children: in_array('needle', call_user_func_array('array_merge', $arr))
Solution 8 - Php
Great function, but it didnt work for me until i added the if($found) { break; } to the elseif
function in_array_r($needle, $haystack) {
$found = false;
foreach ($haystack as $item) {
if ($item === $needle) {
$found = true;
break;
} elseif (is_array($item)) {
$found = in_array_r($needle, $item);
if($found) {
break;
}
}
}
return $found;
}
Solution 9 - Php
Since PHP 5.6 there is a better and cleaner solution for the original answer :
With a multidimensional array like this :
$a = array(array("Mac", "NT"), array("Irix", "Linux"))
We can use the splat operator :
return in_array("Irix", array_merge(...$a), true)
If you have string keys like this :
$a = array("a" => array("Mac", "NT"), "b" => array("Irix", "Linux"))
You will have to use array_values in order to avoid the error Cannot unpack array with string keys :
return in_array("Irix", array_merge(...array_values($a)), true)
Solution 10 - Php
You could always serialize your multi-dimensional array and do a strpos:
$arr = array(array("Mac", "NT"), array("Irix", "Linux"));
$in_arr = (bool)strpos(serialize($arr),'s:4:"Irix";');
if($in_arr){
echo "Got Irix!";
}
Various docs for things I used:
Solution 11 - Php
I believe you can just use array_key_exists nowadays:
<?php
$a=array("Mac"=>"NT","Irix"=>"Linux");
if (array_key_exists("Mac",$a))
{
echo "Key exists!";
}
else
{
echo "Key does not exist!";
}
?>
Solution 12 - Php
The accepted solution (at the time of writing) by jwueller
function in_array_r($needle, $haystack, $strict = false) {
foreach ($haystack as $item) {
if (($strict ? $item === $needle : $item == $needle) || (is_array($item) && in_array_r($needle, $item, $strict))) {
return true;
}
}
return false;
}
Is perfectly correct but may have unintended behaviuor when doing weak comparison (the parameter $strict = false).
Due to PHP's type juggling when comparing values of different type both
"example" == 0
and
0 == "example"
Evaluates true because "example" is casted to int and turned into 0.
(See Why does PHP consider 0 to be equal to a string?)
If this is not the desired behaviuor it can be convenient to cast numeric values to string before doing a non-strict comparison:
function in_array_r($needle, $haystack, $strict = false) {
foreach ($haystack as $item) {
if( ! $strict && is_string( $needle ) && ( is_float( $item ) || is_int( $item ) ) ) {
$item = (string)$item;
}
if (($strict ? $item === $needle : $item == $needle) || (is_array($item) && in_array_r($needle, $item, $strict))) {
return true;
}
}
return false;
}
Solution 13 - Php
This is the first function of this type that I found in the php manual for in_array. Functions in the comment sections aren't always the best but if it doesn't do the trick you can look in there too :)
<?php
function in_multiarray($elem, $array)
{
// if the $array is an array or is an object
if( is_array( $array ) || is_object( $array ) )
{
// if $elem is in $array object
if( is_object( $array ) )
{
$temp_array = get_object_vars( $array );
if( in_array( $elem, $temp_array ) )
return TRUE;
}
// if $elem is in $array return true
if( is_array( $array ) && in_array( $elem, $array ) )
return TRUE;
// if $elem isn't in $array, then check foreach element
foreach( $array as $array_element )
{
// if $array_element is an array or is an object call the in_multiarray function to this element
// if in_multiarray returns TRUE, than return is in array, else check next element
if( ( is_array( $array_element ) || is_object( $array_element ) ) && $this->in_multiarray( $elem, $array_element ) )
{
return TRUE;
exit;
}
}
}
// if isn't in array return FALSE
return FALSE;
}
?>
Solution 14 - Php
Here is my proposition based on json_encode() solution with :
- case insensitive option
- returning the count instead of true
- anywhere in arrays (keys and values)
If word not found, it still returns 0 equal to false.
function in_array_count($needle, $haystack, $caseSensitive = true) {
if(!$caseSensitive) {
return substr_count(strtoupper(json_encode($haystack)), strtoupper($needle));
}
return substr_count(json_encode($haystack), $needle);
}
Hope it helps.
Solution 15 - Php
I was looking for a function that would let me search for both strings and arrays (as needle) in the array (haystack), so I added to the answer by @jwueller.
Here's my code:
/**
* Recursive in_array function
* Searches recursively for needle in an array (haystack).
* Works with both strings and arrays as needle.
* Both needle's and haystack's keys are ignored, only values are compared.
* Note: if needle is an array, all values in needle have to be found for it to
* return true. If one value is not found, false is returned.
* @param mixed $needle The array or string to be found
* @param array $haystack The array to be searched in
* @param boolean $strict Use strict value & type validation (===) or just value
* @return boolean True if in array, false if not.
*/
function in_array_r($needle, $haystack, $strict = false) {
// array wrapper
if (is_array($needle)) {
foreach ($needle as $value) {
if (in_array_r($value, $haystack, $strict) == false) {
// an array value was not found, stop search, return false
return false;
}
}
// if the code reaches this point, all values in array have been found
return true;
}
// string handling
foreach ($haystack as $item) {
if (($strict ? $item === $needle : $item == $needle)
|| (is_array($item) && in_array_r($needle, $item, $strict))) {
return true;
}
}
return false;
}
Solution 16 - Php
It works too creating first a new unidimensional Array from the original one.
$arr = array("key1"=>"value1","key2"=>"value2","key3"=>"value3");
foreach ($arr as $row) $vector[] = $row['key1'];
in_array($needle,$vector);
Solution 17 - Php
Shorter version, for multidimensional arrays created based on database result sets.
function in_array_r($array, $field, $find){
foreach($array as $item){
if($item[$field] == $find) return true;
}
return false;
}
$is_found = in_array_r($os_list, 'os_version', 'XP');
Will return if the $os_list array contains 'XP' in the os_version field.
Solution 18 - Php
I found really small simple solution:
If your array is :
Array
(
[details] => Array
(
[name] => Dhruv
[salary] => 5000
)
[score] => Array
(
[ssc] => 70
[diploma] => 90
[degree] => 70
)
)
then the code will be like:
if(in_array("5000",$array['details'])){
echo "yes found.";
}
else {
echo "no not found";
}
Solution 19 - Php
I used this method works for any number of nested and not require hacking
<?php
$blogCategories = [
'programing' => [
'golang',
'php',
'ruby',
'functional' => [
'Erlang',
'Haskell'
]
],
'bd' => [
'mysql',
'sqlite'
]
];
$it = new RecursiveArrayIterator($blogCategories);
foreach (new RecursiveIteratorIterator($it) as $t) {
$found = $t == 'Haskell';
if ($found) {
break;
}
}
Solution 20 - Php
I have found the following solution not very clean code but it works. It is used as an recursive function.
function in_array_multi( $needle, $array, $strict = false ) {
foreach( $array as $value ) { // Loop thorugh all values
// Check if value is aswell an array
if( is_array( $value )) {
// Recursive use of this function
if(in_array_multi( $needle, $value )) {
return true; // Break loop and return true
}
} else {
// Check if value is equal to needle
if( $strict === true ) {
if(strtolower($value) === strtolower($needle)) {
return true; // Break loop and return true
}
}else {
if(strtolower($value) == strtolower($needle)) {
return true; // Break loop and return true
}
}
}
}
return false; // Nothing found, false
}
Solution 21 - Php
Many of these searches are usually for finding things in a list of records, as some people have pointed out is really a 2-dimensional array.
This is for a list of records that have a uniform set of keys) such as a list of records grabbed from a database, among other things.
Included are both 'in_array' and 'key_exists' styled functions for this structure for completeness. Both functions return a simple true/false boolean answer.
Example 2-dimensional array of records...
$records array:
[0] => Array
(
[first_name] => Charlie
[last_name] => Brown
)
[1] => Array
(
[first_name] => Fred
[last_name] => Sanford
)
Functions:
function in_multidimensional_array($array, $column_key, $search) {
return in_array($search, array_column($array, $column_key));
}
function multidimensional_array_key_exists($array, $column_key) {
return in_array($column_key, array_keys(array_shift($array)));
}
Tests:
var_dump(in_multidimensional_array($records, 'first_name', 'Charlie')); // true
var_dump(multidimensional_array_key_exists($records, 'first_name')); // true
Solution 22 - Php
Please try:
in_array("irix",array_keys($b))
in_array("Linux",array_keys($b["irix"])
Im not sure about the need, but this might work for your requirement
Solution 23 - Php
what about array_search? seems it quite faster than foreach according to https://gist.github.com/Ocramius/1290076 ..
if( array_search("Irix", $a) === true)
{
echo "Got Irix";
}
Solution 24 - Php
you can use like this
$result = array_intersect($array1, $array2);
print_r($result);