How to do an intersection of arrays of arrays - php

Question

I’m trying to do a function in php that try to make an intersection of an array of arrays. I have found array_intersect($resultx,$resulty); but it's working just for tables with one value. In my case I have arrays of arrays like that.
Array
(
[0] => Array
(
[name] => Chris
[id] => 1033
)
[1] => Array
(
[name] => Vins
[id] => 1034
)
[2] => Array
(
[name] => Steve
[id] => 1035
)
[3] => Array
(
[name] => Henry
[id] => 1036
)
[4] => Array
(
[name] => Jack
[id] => 1037
)
[5] => Array
(
[name] => Paul
[id] => 1038
)
)
To resume my problem I’m trying to make an intersection of lot of tables like the one i have mentioned. So any idea
examples tab1[[1,2,3],[2,3,1]] tab2[[1,2,3],[5,7,7] the result will be tab3[[1,2,3]] it is clear for you ?
Thanks

Answer 1

#KANDROID OS, Please check below example for intersection of arrays.
Suppose you have two array(s) like below:
$arr1 = array(
array('name' => 'Chris','id' => '1111'),
array('name' => 'Vins','id' => '1112'),
array('name' => 'Steve','id' => '1113'),
);
$arr2 = array(
array('name' => 'Chris','id' => '1111'),
array('name' => 'dddd','id' => '2222'),
);
You can use array_uintersect() to use a custom comparison function, like this:
$intersect = array_uintersect($arr1, $arr2, 'comparevalue');
print_r($intersect);
function comparevalue($val1, $val2)
{
return strcmp($val1['id'], $val2['id']);
}
So Outcome of above is like below :
Array
(
[0] => Array
(
[name] => Chris
[id] => 1111
)
)

Answer 2

You could recursively do it like this:
$arr1 = array(
array('name' => 'Chris', 'id' => '1033'),
array('name' => 'Vins', 'id' => '1034'),
array('name' => 'Steve', 'id' => '1035'),
array('name' => 'Henry', 'id' => '1036'),
array('name' => 'Jack', 'id' => '1037'),
);
$find = array( // Array for ANY search criteria,
array(1033), // name, id, etc.
array('Vins') // (Each element needs to be an array)
);
$match = array(); // Define array for results
for($i=0; $i < count($arr1); $i++){ // For every "name/id combo",
for($j = 0; $j < count($find); $j++){ // go through every search criteria
$thisMatch = array_intersect( $arr1[$i], $find[$j]); // and check for a match
if ($thisMatch){ // If a match was found,
$match[] = $arr1[$i]; // add it to the results array
}
}
}
var_dump($match);
This will result in:
Array
[0] =>
Array (
'name' => string 'Chris'
'id' => string '1033'
)
[1] =>
Array (
'name' => string 'Vins' (length=4)
'id' => string '1034' (length=4)
)
You have to be careful though, with the example using the callback, trying to use the intersect for 'name' AND 'id' values WILL NOT return paired values as you might expect. It only needs to find one of the values, so if you try to search for a 'name' that corresponds to a different 'id', you will get both items back, even if that "combination" doesn't exist. It will do the same thing even if you use the keys in the search like this:
$find = array(
array('id' => 1033),
array('name' => 'Vins')
);
I just noticed that issue so I thought I'd bring it up. Depending on what you're trying to do, you may need some sort of recursive aspect anyway, like I've shown.
Hope this helps :)