Using array_diff to Check for Array Value Inclusion

Determining whether an array contains all values from another array is a common programming task. Consider the following example:

Given arrays $all and $search_this, defined as:

$all = array
(
    0 => 307,
    1 => 157,
    2 => 234,
    3 => 200,
    4 => 322,
    5 => 324
);
$search_this = array
(
    0 => 200,
    1 => 234
);

We aim to verify if $all includes all the elements present in $search_this.

Utilizing array_diff for Efficient Comparison

To achieve this comparison, the most efficient approach is to utilize the array_diff function, which returns an array of elements found in the first array but not in the second. By applying it to our case, we can deduce whether $all contains all values from $search_this.

$containsAllValues = !array_diff($search_this, $all);

If the resultant array is empty (i.e., no difference is found), it implies that $all contains all the values from $search_this. As a result, $containsAllValues will be set to true. Otherwise, it will be false. This method effectively resolves the problem with minimal complexity and straightforward implementation.