Most efficient way to check if array element exists in string - php

Question

I've been looking for a way to check if any of an array of values exists in a string, but it seems that PHP has no native way of doing this, so I've come up with the below.
My question - is there a better way of doing this, as this seems pretty inefficient? Thanks.
$match_found = false;
$referer = wp_get_referer();
$valid_referers = array(
'dd-options',
'dd-options-footer',
'dd-options-offices'
);
/** Loop through all referers looking for a match */
foreach($valid_referers as $string) :
$referer_valid = strstr($referer, $string);
if($referer_valid !== false) :
$match_found = true;
continue;
endif;
endforeach;
/** If there were no matches, exit the function */
if(!$match_found) :
return false;
endif;

Answer 1

Try with following function:
function contains($input, array $referers)
{
foreach($referers as $referer) {
if (stripos($input,$referer) !== false) {
return true;
}
}
return false;
}
if ( contains($referer, $valid_referers) ) {
// contains
}

Answer 2

What about this:
$exists = true;
array_walk($my_array, function($item, $key) {
$exists &= (strpos($my_string, $item) !== FALSE);
});
var_dump($exists);
This will check if any of the array values exists in the string. If only one is missing, You are given a false response. Should You need to find out which one are not present in the string, try this:
$exists = true;
$not_present = array();
array_walk($my_array, function($item, $key) {
if(strpos($my_string, $item) === FALSE) {
$not_present[] = $item;
$exists &= false;
} else {
$exists &= true;
}
});
var_dump($exists);
var_dump($not_present);

Answer 3

First of, alternate syntax is nice to use, but historically it's used in template files. Since it's structure is easily readable while coupling/decouping the PHP interpreter to interpolate HTML data.
Second, it's generally wise if all your code does is to check something, to immediately return if that condition is met:
$match_found = false;
$referer = wp_get_referer();
$valid_referers = array(
'dd-options',
'dd-options-footer',
'dd-options-offices'
);
/** Loop through all referers looking for a match */
foreach($valid_referers as $string) :
$referer_valid = strstr($referer, $string);
if($referer_valid !== false) :
$match_found = true;
break; // break here. You already know other values will not change the outcome
endif;
endforeach;
/** If there were no matches, exit the function */
if(!$match_found) :
return false;
endif;
// if you don't do anything after this return, it's identical to doing return $match_found
Now as specified by some of the other posts in this thread. PHP has a number of functions that can help. Here's a couple more:
in_array($referer, $valid_referers);// returns true/false on match
$valid_referers = array(
'dd-options' => true,
'dd-options-footer' => true,
'dd-options-offices' => true
);// remapped to a dictionary instead of a standard array
isset($valid_referers[$referer]);// returns true/false on match
Ask if you have any questions.