hi monks

i think i didn't ask my question right last time, but i've done a lot of experiments. anyway, supposing my data looks like this (more or less same as last time): 

$ids{'foo'}-> [ 3, 4, 5 ];
$ids{'bar'}-> [ 3 ];
$ids{'zoo'}-> [ 3, 4, 5 ];

[download]

I want the intersection of those three arrays. That is, in the above example, the correct answer is [ 3 ].

Here's 2 other examples: 

$ids{'foo'}-> [ 5 ];

[download]
answer: [ 5 ] 

$ids{'foo'}->[ 3, 4, 5, 6 ];
$ids{'bar'}->[ 4, 5, 6, 7 ];
$ids{'zoo'}->[ 5, 6, 7, 8 ];

[download]
answer is [ 5, 6 ] 

$ids{'foo'}->[ 3, 4, 5, 6 ];
$ids{'bar'}->[ 4, 5, 6, 7 ];
$ids{'zoo'}->[ 5, 6, 7, 8 ];
$ids{'goo'}->[ 9, 10, 11  ];

[download]
answer: [ ] # undef

i don't care to know which $id they were in, i JUST want the array that represents elements that showed up at least once in ALL arrays. thanks!

In reply to intersection of N arrays by basscakes

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