Question

Suppose a string:

$str = 'a_b_c';

I want match all possible combination with a, b, c with above. For example:

b_a_c, c_a_b, a_c_b..etc will be give true when compare with above $str.

NOTE:

$str may be random. eg: a_b, k_l_m_n etc

Answer 1

I would split your string into an array, and then compare it to an array of elements to match on.

$originalList = explode('_', 'a_b_c');
$matchList = array('a', 'b', 'c');
$diff = array_diff($matchList, $originalList);
if (!empty($diff)) {
    // At least one of the elements in $matchList is not in $originalList
}

Beware of duplicate elements and what not, depending on how your data comes in.

Documentation:

• array_diff()
• explode()