Custom array comparing function

Question

This custom function is comparing two arrays, but if the arrays are completely different, i´ll get the error "Undefined variable: c". How can i fix this?

function myIntersect($a, $b) {
    foreach ($a as $x) {
        $i = array_search($x, $b);
        if ($i !== false) {
            $c[] = $x;
            unset($b[$i]);
        }
    }
    return $c;
}

Results:

$arrayone = array("3", "2", "1", "2", "3");
$arraytwo = array("1", "2", "3", "2", "1");
$result = myIntersect($arrayone, $arraytwo);
print_r($result); // ["3", "2", "1", "2"]

`$c = array()` before foreach – M A SIDDIQUI Apr 13 '17 at 08:58 — M A SIDDIQUI, Apr 13 '17 at 08:58

score 1 · Accepted Answer · answered Apr 13 '17 at 08:58

1

add this to your function now it will define an empty array else you can define as boolean false. $c=array();

function myIntersect($a, $b) {
    $c=array();//add this to your function now it will define an empty array else you can define as boolean false
    foreach ($a as $x) {
        $i = array_search($x, $b);
        if ($i !== false) {
            $c[] = $x;
            unset($b[$i]);
        }
    }
    return $c;
}

answered Apr 13 '17 at 08:58

Sahil Gulati

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Perfect! Thank you very much! – blasthrop Apr 13 '17 at 09:01
@blasthrop welcome.... :) – Sahil Gulati Apr 13 '17 at 09:02

Custom array comparing function

1 Answers1