PHP – Check if value exists in array but only for specific key
I have an array and I am checking if a value exists in the array using in_array(). However, I want to check only in the ID key and not date.
$arr = ({ "ID":"10", "date":"04\/22\/20" }, { "ID":"20", "date":"05\/25\/20" }, { "ID":"32", "date":"07\/13\/20" }); So in this example, the condition should not be met since 25 exists in date, but not in ID.
if (in_array("25", $arr)) { return true; } 
To directly do this, you need to loop over the array.
function hasId($arr, $id) { foreach ($arr as $value) { if ($value['ID'] == $id) return true; } return false; } If you need to do this for several IDs, it is better to convert the array to a map and use isset.
$map = array(); foreach ($arr as $value) { $map[$value['ID']] = $value; // or $map[$value['ID']] = $value['date']; } if (isset($map["25"])) { ... } This will also allow you to look up any value in the map cheaply by id using $map[$key].
For versions of PHP (>= 5.5.0), there is a simple way to do this
$arr = ({ "ID":"10", "date":"04\/22\/20" }, { "ID":"20", "date":"05\/25\/20" }, { "ID":"32", "date":"07\/13\/20" }); $searched_value = array_search('25', array_column($arr, 'ID')); Here is documentation for array_column.
You can also check it by array_filter function:
$searchId = '25'; $arr = [[ "ID" => "10", "date" => "04\/22\/20" ], [ "ID" => "25", "date" => "05\/25\/20" ], [ "ID" => "32", "date" => "07\/13\/20" ]]; $items = array_filter($arr, function ($item) use ($searchId) { return $item['ID'] === $searchId; }); if (count($items) > 0) { echo 'found'; }; 
