PHP: Check if array contains another array values (in specific order)

Question

I have an array:

$haystack = array(1,2,3,4,5,6,7,8,9,10...);
$needle = array(3,4,5);
$bad_needle = array(3,5,4);

And I need to got true if I check if haystack contains a needle. But I also need false if I check if haystack contains bad_needle. Tip without foreach for all haystacks and needles?

http://stackoverflow.com/questions/12867315/checking-if-an-array-contains-all-elements-of-another-array does that answer your question? — Harri, Oct 29 '13 at 20:09
This seems like homework. Please post what you have tried so far. — puelo, Oct 29 '13 at 20:09
**Tip:** Have a look under **Related** over to the right >>> — Funk Forty Niner, Oct 29 '13 at 20:09

deceze · Accepted Answer · 2013-10-29T20:18:24.547

$offset = array_search($needle[0], $haystack);
$slice  = array_slice($haystack, $offset, count($needle));
if ($slice === $needle) {
    // yes, contains needle
}

This fails if the values in $haystack are not unique though. In this case, I'd go with a nice loop:

$found  = false;
$j      = 0;
$length = count($needle);

foreach ($haystack as $i) {
    if ($i == $needle[$j]) {
        $j++;
    } else {
        $j = 0;
    }
    if ($j >= $length) {
        $found = true;
        break;
    }
}

if ($found) {
    // yes, contains needle
}

AbraCadaver · Answer 2 · 2013-10-29T21:25:13.560

0

var_dump(strpos(implode(',', $haystack), implode(',', $needle)) !== false);

var_dump(strpos(implode(',', $haystack), implode(',', $bad_needle)) !== false);

A working array_slice() would still need a loop as far as I can work out:

foreach(array_keys($haystack, reset($needle)) as $offset) {
    if($needle == array_slice($haystack, $offset, count($needle))) {
        // yes, contains needle
        break;
    }
}

edited Oct 29 '13 at 21:25

answered Oct 29 '13 at 20:40

AbraCadaver

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And please, this should be faster than array_slice? – Anette D. Oct 29 '13 at 21:01
@Anette D.: I haven't timed it, but it doesn't fail like the array slice() example. – AbraCadaver Oct 29 '13 at 21:04
Array_slice works for your specific example, but not: `$haystack = array(1,2,3,3,4,5,6,7,8,9,10);` – AbraCadaver Oct 29 '13 at 21:10
Added working array_slice(). Shouldn't use $needle[0] cuz it could be any number or associative. – AbraCadaver Oct 29 '13 at 21:21

PHP: Check if array contains another array values (in specific order)

2 Answers2