Test if one array is a subset of another

Question

How can I determine if one array is a subset of another (all elements in the first are present in the second)?

 $s1 = \"string1>string2>string3>string4&         


        

Answer 1

if (array_intersect($array1, $array2) == $array1) {
    // $array1 is a subset of $array2
}