php how to check if array[1] not exist code example

Example 1: check if array has value php

$myArr = [38, 18, 10, 7, "15"];

echo in_array(10, $myArr); // TRUE
echo in_array(19, $myArr); // TRUE

// Without strict check
echo in_array("18", $myArr); // TRUE
// With strict check
echo in_array("18", $myArr, true); // FALSE

Example 2: check null in_array php

if (!empty($data_days) && in_array(1, $data_days, true)){ // use numeric value 1, not string