如何在数组中搜索以查找包含特定值的所有子数组

Question

i have a array placed in the variable $class that is constituted of sub arrays containing 2 student id's each, i am trying to find all the sub arrays that contain a certain id for example 11 i want to keep all arrays containing this id in a variable.

array example

Array
(
    [0] => Array
        (
            [s1] => 6
            [s2] => 37
        )

    [1] => Array
        (
            [s1] => 8
            [s2] => 11
        )

    [2] => Array
        (
            [s1] => 11
            [s2] => 48
        )

)

code

foreach ($class as $key => $value) {
    if(!in_array($id, $class)){
        unset($class[$key]);
    }
}

Answer 1

You are close. If you loop and reference the correct variable with the in_array(), it would work as you hopefully need. Then assign the matching array into a new array var to use later (so you are not altering your original array!):

$id = 11;
$matched = array();
foreach ($class as $i => $students) {
    if ( in_array($id, $students) ) {
        $matched[] = $class[$i];
    }
}

print_r($matched);

Would result in:

Array (
     [0] => Array
         (
             [s1] => 8
             [s2] => 11
         )
     [1] => Array
         (
             [s1] => 11
             [s2] => 48
         )
     )

Answer 2

Associative array http://php.net/manual/es/function.array-search.php

$class = array(array("s1"=>6, "s2"=>37),array("s1"=>8,"s2"=>11),array("s1"=>11, "s2"=>48));
$id = 11;
foreach ($class as $key => $value) {
    if(!array_search($id, $value)){
        unset($class[$key]);
    }
}

Sorry, you can follow this answers using array_search for multi dimensional array