Set array values and preserve keys

[NotionCommotion]

How can I get [4=>[],5=>[],8=>[]] from $arr?  Guess I will just walk it, but thought there would be a more intuitive way to do so.  Not a big deal, but $arr is still needed so I will need to create a copy.  Thanks

$arr=[4=>[],5=>['a','b','c'],8=>[1,3,4]];
$arr1=array_fill_keys($arr,[]);
$arrCopy=$arr;
array_walk($arrCopy,function(&$v){$v=[];});

[kicken]

Do you want to keep the keys, but reset all their values to empty array's? Not really sure what you're asking/trying to do.

 

If you just want the keys + empty array values then you could just do this:

$arr2 = array_fill_keys(array_keys($arr), []);

[NotionCommotion]

Perfect!  Thanks.  I was giving array_fill_keys() an array who's keys instead of values were what I desired.