How do I multiply the arrays (as SQL does)

Question

Let's say I have several arrays:

$array1 = array( 'a','b','c');
$array2 = array( '1','2','3');
$array3 = array( '+','-');

As a result I'd like to have a array of all possible mixes of those arrays:

$result = array( 'a1+','a1-','a2+','a2-','b1+','b1-','b2+'...

SQL provides such operation in case of the following request:

SELECT * FROM `letters`,`digits`,`operations`

Ho can I do this in PHP?

Use Linq cross join[1] feature It will do what you wish. [1]: http://stackoverflow.com/questions/56547/how-do-you-perform-a-cross-join-with-linq-to-sql — Charles Bretana, May 27 '13 at 18:00
This is called the 'cartesian product', and there is a useful answer here: http://stackoverflow.com/a/6313346/1064767 — Sammitch, May 27 '13 at 18:04

score 0 · Accepted Answer · answered May 27 '13 at 18:05

0

$permute= array();
foreach($array1 as $x)
    foreach($array2 as $y)
        foreach ($array3 as $z)
            $permute[]= $x.$y.$z;

answered May 27 '13 at 18:05

Orangepill

Thanks! Is it possible to convert this function to do this for any amount of arrayN-s? Please help me to build this recurring function... – Roman Matveev May 29 '13 at 20:42

1 Answers1