PHP in_array Vs array_search
Assalamualaikum , I am going to explain the difference between mostly used PHP built-in function. What I faced when implementing these function on a particular web application.
in_array
in_array — Checks if a value exists in an array
in_array ( mixed $needle , array $haystack [, bool $strict = FALSE ] ) : bool
Searches for needle in haystack using loose comparison unless strict is set.
needle : The searched value.If needle is a string, the comparison is done in a case-sensitive manner.
haystack: The array.
strict: If the third parameter strict is set to TRUE then the in_array() function will also check the types of the needle in the haystack.
Return Values : Returns TRUE if needle is found in the array, FALSE otherwise.
<?php
$os = array(“Mac”, “NT”, “Irix”, “Linux”);
if (in_array(“Irix”, $os)) {
echo “Got Irix”;
}
if (in_array(“mac”, $os)) {
echo “Got mac”;
}
?>
The second condition fails because in_array() is case-sensitive, so the program above will display:
Got Irixarray_search()
array_search — Searches the array for a given value and returns the first corresponding key if successful
array_search ( mixed $needle , array $haystack [, bool $strict = FALSE ] ) : mixed
Searches for needle in haystack.
Return Value: Returns the key for needle if it is found in the array, FALSE otherwise.
Get Kazi Badrul Alam’s stories in your inbox
Join Medium for free to get updates from this writer.
<?php
$arr = array(“nice”,”car”,”none”);
var_dump(array_search(“car”, ($arr)));
This function may return Boolean FALSE, but may also return a non-Boolean value which evaluates to FALSE. Please read the section on Booleans for more information. Use the === operator for testing the return value of this function.
non-Boolean value which evaluates to FALSE
$array = [“a”,”b”,”c”,”d”];
$key = array_search(“a”, $array); //$key = 0
if ($key)
{
//even a element is found in array, but if (0) means false
//…
}
//the correct way
if (false !== $key)
{
echo $key;
}
OR
if(in_array(‘a’, $array)){
$key = array_search(‘a’, $array)
unlink($array[$key]);
}
Conclusion:
array_search return key if found else return false
array_search: If needle is found in haystack more than once, the first matching key is returned.
in_array return true if found else return false
If you’re working with very large 2 dimensional arrays (eg 20,000+ elements) it’s much faster to do this…
<?php
$needle = ‘test for this’;
$flipped_haystack = array_flip($haystack);
if ( isset($flipped_haystack[$needle]) )
{
print “Yes it’s there!”;
}
?>
array_flip — Exchanges all keys with their associated values in an array
