How can it be ensured that all values from one array must be present in another array to return true?

To ensure that all values from one array must be present in another array to return true, you can use the array_diff() function to find the difference between the two arrays. If the result is an empty array, it means that all values from the first array are present in the second array.

$array1 = [1, 2, 3, 4, 5];
$array2 = [2, 3, 4];

$result = array_diff($array1, $array2);

if (empty($result)) {
    echo "All values from array1 are present in array2.";
} else {
    echo "Not all values from array1 are present in array2.";
}