How to use PHP in_array with associative array?

Question

Is there any php function such as in_array for associative arrays you get by the mysql function "mysql_fetch assoc" ?

For example, if I have an $array that looks like this:

array(0=>(array(ID=>1, name=>"Smith"), 1=>(array(ID=>2, name=>"John"))

Can I do something like in_array(key,value,array)?

Or in my case, if I am looking for the ID value of "1", in_array("ID",1,$array).

This is my solution, comment on it if you think it's the right way:

function in_assoc_array($key,$value,$array)
{
    if (empty($array))
        return false;
    else
    {
        foreach($array as $a)
        {
            if ($a[$key] == $value)
                return true;
        }
        return false;
    }
}

I think you want to compare the key/value pair with your given value. right? — Rahil Wazir, Feb 16 '14 at 08:53

score 46 · Answer 1 · answered Dec 22 '15 at 20:00

46

In your case, I wonder if simply using isset() makes more sense, i.e.

isset($a[$key])

answered Dec 22 '15 at 20:00

Phil LaNasa

2,907
1
25
16

2

isset we use when we know the key and array is designed in that way. sometimes we have to in_array for searching – rajangupta Apr 19 '16 at 11:57
Your light, simple and elegant solution works and that is how it should be. Thank You @Phil LaNAsa – Samuel Ramzan Aug 09 '22 at 17:55

Clinton Dobbs · Answer 2 · 2021-11-12T07:40:17.440

19

Here is a one liner you can use.

$isInArray = in_array(1, array_column($names, 'ID'));

$isInArray = a Boolean (true or false) defining whether the value given was found within the column requested of the array in question.

1 = The value that is being searched for within the array.

$names = The array in question.

'ID' = The column within the array where we are searching for the value of 1.

edited Nov 12 '21 at 07:40

answered Apr 10 '20 at 16:31

Clinton Dobbs

561
5
6

1

that's perfectly works, saved my day, this is also perfect for 2 foreach loops and checkboxes populated using laravel projects – Imran_Developer Jun 04 '22 at 13:15

score 17 · Accepted Answer · answered Feb 16 '14 at 09:29

17

Try this..... You can use this function for any depth of the associated array. Just contraint to this function is that the key value would not be repeat any where in array.

<?php 
function is_in_array($array, $key, $key_value){
      $within_array = 'no';
      foreach( $array as $k=>$v ){
        if( is_array($v) ){
            $within_array = is_in_array($v, $key, $key_value);
            if( $within_array == 'yes' ){
                break;
            }
        } else {
                if( $v == $key_value && $k == $key ){
                        $within_array = 'yes';
                        break;
                }
        }
      }
      return $within_array;
}
$test = array(
                0=> array('ID'=>1, 'name'=>"Smith"), 
                1=> array('ID'=>2, 'name'=>"John")
        );
print_r(is_in_array($test, 'name', 'Smith'));
?>

answered Feb 16 '14 at 09:29

I don't udnerstand why you wrote a new code, when there is a built-in function for that. You can see it below. On an other point the `$k` variable is waste of memory space, because it should check the value only. – PumpkinSeed Nov 17 '16 at 11:47
@AndrewJarvis although it has been a while, why do you say that? – Jacob Cohen Jan 01 '17 at 07:28
@JacobCohen A foreach loop on the top-level array and a simple `if (isset($array["ID"]) && $array["ID"] === 1) {}` will do the trick with much less code. – Jarvl Oct 14 '19 at 18:10
Nice answer ... works for me – deemi-D-nadeem Jan 04 '22 at 10:08

Shankar Narayana Damodaran · Answer 4 · 2014-02-16T09:08:50.820

10

You can't do it directly on nested arrays.. You need to nest it down a bit and then do it.

<?php
$arr=array(0=>array('ID'=>1, 'name'=>"Smith"), 1=>array('ID'=>2, 'name'=>"John"));

foreach($arr as $arr1)
{
    if(in_array(1,$arr1))
    {
       echo "Yes found.. and the correspoding key is ".key($arr1)." and the employee is ".$arr1['name'];
    }
}

OUTPUT :

Yes found.. and the correspoding key is ID and the employee is Smith

edited Feb 16 '14 at 09:08

answered Feb 16 '14 at 08:52

Shankar Narayana Damodaran

68,075
43
96
126

Guess I'ma just have to write my own function for it then huh? – Jacob Cohen Feb 16 '14 at 08:53
1

Nope just do a `foreach` and you can do it inside of that. – Shankar Narayana Damodaran Feb 16 '14 at 08:55
I edited my post, look at the code and tell me if you think its right, or if there's a way to make it better. – Jacob Cohen Feb 16 '14 at 08:58
@JacobCohen, See the edited answer are you looking something similar like this ? – Shankar Narayana Damodaran Feb 16 '14 at 09:02
1

Almost! I wanted to do it for a specific key I pick. I managed to write it on my own though, thanks for the muse. – Jacob Cohen Feb 16 '14 at 09:34

score 8 · Answer 5 · edited Aug 28 '15 at 15:24

First you must know which part of the associative array you're going to use as haystack in in_array function. Then you can use in_array without additional code.

Example with values :

<?php
$assoc = array(1 => "apple", 2 => "banana", 3 => "lemon", 4 => "pear");
$haystack = array_values($assoc);
echo "<p>" . print_r($assoc, true) . "</p>";

$needle = 'banana';
$find = (in_array($needle, $haystack)) ? 'TRUE' : 'FALSE';
echo "<p>$needle : $find</p>";

$needle = 'cherry';
$find = (in_array($needle, $haystack)) ? 'TRUE' : 'FALSE';
echo "<p>$needle : $find</p>";
?>

Results in :

Array ( [1] => apple [2] => banana [3] => lemon [4] => pear )

banana : TRUE

cherry : FALSE

score 4 · Answer 6 · edited Jul 20 '21 at 13:47

4

Syntax

 in_array(mixed $needle, array $haystack, bool $strict = false): bool

Needle can be mixed type, so it can be any type, no issues if it is a numeric or associative array.

in_array('foo',array_unique(array_keys($array)));

edited Jul 20 '21 at 13:47

Prafulla Kumar Sahu

9,321
11
68
105

answered Jul 20 '21 at 09:35

dılo sürücü

3,821
1
26
28

Ivan Ferrer · Answer 7 · 2017-09-04T21:25:04.643

The sample formule, using class and methods:

class VerifyInArray
{
 public function getMyCollection($field, $collection)
 {
     $list = array();
     if (count($collection)) {
        foreach ($collection as $k => $val) {
            $list[] = $val[$field];
        }
     }
     return $list;
 }

public function inMyArray($collection, $field, $findValue)
{
    if (isset($collection[0])) {
        if (array_key_exists($field, $collection[0]) == false) {
           return 'no'; 
        }
    }

    if (in_array($findValue, $this->getMyCollection($field, $collection))) {
        return 'ok';
    }
    return 'no';
}

public function displayInArray($collection, $attr, $value)
{
   return 'search result: '. $this->inMyArray($collection, $attr, $value);
}

}
$src = new VerifyInArray();

 $collection = array(
         array(
               'ID' => 1, 
               'name' => 'Smith'
         ), 
         array(
               'ID' => 2, 
               'name' => 'John'
         )
    );
echo $src->displayInArray($collection, 'ID', 2). "\n<br>" .
     $src->displayInArray($collection, 'ID', 0);

Model in ideone

How to use PHP in_array with associative array?

7 Answers7

Linked