Check if array is subset of another

[ecopetition]

Hi, I've checked the PHP manual and Googled this but can't find anything that assists me.

 

Does anybody know if there exists a function issubset($childarray, $parentarray) that returns true if $childarray is a subset of $parentarray?  That is, if all the elements in $childarray are included in $parentarray.

 

Many thanks

[trq]

array_diff will provide you with a solution.

[ecopetition]

Thanks for your reply thorpe, but this function returns the difference in the arrays, how would one use that to see if it's a subarray of the parent array?

 

I read the notes for the function and didn't get anything similar to what I want, also Googled and it seems to have very few results for "subarray".

 

Thanks again.

[litebearer]

Perhaps write your own???

<?PHP
function issubset($childarray, $parentarray);
$c = count($childarray);
$valid = 1;
for($i=0;$i<$c;$i++) {
	if(!in_array($childarray[$i], $parentarray)) {
		$valid = 0;
		return $valid;
	}
}
return $valid;
}
?>

[PFMaBiSmAd]

You can probably use array_intersect , followed by an array_diff to find if all the elements in one array are found in another array.

[PFMaBiSmAd]

Or an array_diff and a few count statements -

 

<?php

$main = range(10,20);

$subarray = array(1,12,13);

$diff = array_diff($main,$subarray);

if(count($diff) == count($main) - count($subarray)){
echo "all elements in the subarray were found in the main array";
} else {
echo "not all the elements in the subarray were found in the main array";
}

[kicken]

A quick array_intersect and count should work.

 

<?php
$a1 = array(2,4,6,;
$a2 = array(1,2,3,4,5,6,7,8,9,10);

function issubset($arr1, $arr2){
    return count($a1)==count(array_intersect($a1, $a2));
}

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