Reindex array after filtering with array_intersect() [duplicate]

Question

I want to find the intersection of elements between two arrays; the result will go to another array.

I've written: $result = array_intersect($arrayone,$arraytwo);

If I write count($result) it returns a correct value, but if I write $result[0] it returns the following notice: Notice: Undefined offset: 0.

I guess the indices are different; Do a var_dump($result) to check. — jgroenen
– jgroenen, Commented Jul 22, 2013 at 12:22

DevZer0 · Accepted Answer · 2013-07-22 12:21:47Z

6

the intersection maintains index. do the following

$result = array_intersect($arrayone,$arraytwo);
$result = array_values($result);

Then you can access with $result[0];

answered Jul 22, 2013 at 12:21

DevZer0

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Jon · Accepted Answer · 2013-07-22 12:21:56Z

4

That is because array_intersect preserves the keys from its first argument. If $arrayone did not have a key 0, $result will also not have one.

If you are not interested in the keys of the result then you can simply reindex it with array_keys($result) and then access the elements given numeric indexes.

However, do keep in mind that directly referring to items inside an array with numeric indexes is somewhat unusual in PHP; in most cases there are more appropriate ways to handle numerically indexed arrays.

answered Jul 22, 2013 at 12:21

Jon

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