PHP compare array

Question

Is there anyway to compare arrays in php using an inbuilt function, short of doing some sort of loop?

$a1 = array(1,2,3);
$a2 = array(1,2,3);

if (array_are_         


        

Answer 1

Compare values of two arrays:

$a = array(1,2,3);
$b = array(1,3,2);

if (array_diff($a, $b) || array_diff($b, $a)) {
    echo 'Not equal';
}else{
    echo 'Equal';
}

Answer 2

Also you can try this way:

if(serialize($a1) == serialize($a2))

Answer 3

Just check $a1 == $a2 -- what's wrong with that?

Answer 4

If you want to search some array inside a big array of arrays (>10k) then much more quickly is comparing serialized arrays (saved in cache). Example from work with URL:

/**
@return array
*/
function createCache()
{
    $cache = [];
    foreach ($this->listOfUrl() as $url => $args)
    {
        ksort($args);
        $cache['url'][$url] = $args;
        $cache['arr'][crc32(serialize($args))] = $url;
    }
    return $cache;
}

/**
@param array $args
@return string
*/
function searchUrl($args)
{
    ksort($params);
    $crc = crc32(serialize($params));        
    return isset($this->cache['arr'][$crc]) ? $this->cache['arr'][$crc] : NULL;                
} 

/**
@param string $url
@return array
*/
function searchArgs($url)
{
    return isset($this->cache['url'][$url]) ? $this->cache['url'][$url] : NULL;
}

Answer 5

@Cleanshooter i'm sorry but this does not do, what it is expected todo: (so does array_diff mentioned in this context)

$a1 = array('one','two');
$a2 = array('one','two','three');

var_dump(count(array_diff($a1, $a2)) === 0); // returns TRUE

(annotation: you cannot use empty on functions before PHP 5.5) in this case the result is true allthough the arrays are different.

array_diff [...] Returns an array containing all the entries from array1 that are not present in any of the other arrays.

which does not mean that array_diff is something like: array_get_all_differences. Explained in mathematical sets it computes:

{'one','two'} \ {'one','two','three'} = {}

which means something like all elements from first set without all the elements from second set, which are in the first set. So that

var_dump(array_diff($a2, $a1));

computes to

array(1) { [2]=> string(5) "three" } 

The conclusion is, that you have to do an array_diff in "both ways" to get all "differences" from the two arrays.

hope this helps :)

Answer 6

verify that the intersections count is the same as both source arrays

$intersections = array_intersect($a1, $a2);
$equality = (count($a1) == count($a2)) && (count($a2) == count($intersections)) ? true : false;