substr_in_array
No matter what I want to do with an array, PHP usually has a first class method that does it. I was therefore surprised that in_array() didn’t handle substring matches. (I was sure there was a flag, but apparently not!)
No doubt everyone has their own version of this, but here’s mine so that I don’t have to recreate it next time:
/**
* A version of in_array() that does a sub string match on $needle
*
* @param mixed $needle The searched value
* @param array $haystack The array to search in
* @return boolean
*/
function substr_in_array($needle, array $haystack)
{
$filtered = array_filter($haystack, function ($item) use ($needle) {
return false !== strpos($item, $needle);
});
return !empty($filtered);
}
Is there a better way of doing this?
I would actually prefer a foreach based implementation because it can return as soon as an match is found.
That may count as micro-optimisation in most cases but the readability is not really hindered .
function substr_in_array($needle, array $haystack) { foreach ($haystack as $item) { if (false !== strpos($item, $needle)) { return true; } } return false; }I might be tempted to use
array_reduceinstead ofarray_filter. Since the question is Does this substring exist in this array? and not How many times does this substring exist in this array? you can abuse PHP's short-circuit evaluation to avoid callingstrposfor every element. This may show useful gains when$haystackis stupid big./** * A version of in_array() that does a sub string match on $needle * * @param mixed $needle The searched value * @param array $haystack The array to search in * @return boolean */ function substr_in_array($needle, array $haystack) { return array_reduce($haystack, function ($inArray, $item) use ($needle) { return $inArray || false !== strpos($item, $needle); }, false); }Using fnmatch() rather than strpos() allows you to do wildcarding and other clever filtering in your search
Don't use
empty()when you're actually looking for(bool)$filtered.I think your use of filter is clever, but I don't agree with the function name. substr() uses start/leght which is in array terms array_slice(), so it sounds weird and misleading. Why not find_in_array? Then you can return the filtered array as the name also don't make any allusion the bool type.
Yeah, A better name would be substring_in_array to avoid any future confusion.