Check arrays to find common data

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Find common values in multiple arrays with PHP

I'm trying to find the number of friends two users have in common. Each users friends user id's are stored in the data base like this: 12, 13, 14. This is my code.

$my_friends = explode(',', $my_friends);
print_r($my_friends);

This outputs: Array ( [0] => 12 [1] => 13 [2] => 14 )

These are my friends user id's. Now for the next user:

$users_friends = explode(',', $users_friends);
print_r($users_friends);

This outputs: Array ( [0] => 12 )

How do I show that user 1 and user 2 have id 12 in common ?

http://stackoverflow.com/questions/5299608/find-common-values-in-multiple-arrays-with-php — Rajat Singhal, Sep 29 '12 at 16:46

score 4 · Answer 1 · answered Sep 29 '12 at 16:47

4

Besides suggesting that you should normalise your database, which would make this easy to do with a simple SQL Query:

Explode the $myFrieds and $users_friends arrays, then use the array_intersect() function to find the common entries, and count() those

answered Sep 29 '12 at 16:47

Mark Baker

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score 1 · Accepted Answer · answered Sep 29 '12 at 16:45

1

You could use array_intersect().

print_r(array_intersect($my_friends, $users_friends));

will output Array ( [0] => 12 )

answered Sep 29 '12 at 16:45

Havelock

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score 1 · Answer 3 · answered Sep 29 '12 at 16:47

1

You can use array_intersect:

$common_friends = array_intersect($my_friends, $users_friends);

answered Sep 29 '12 at 16:47

Nelson

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Check arrays to find common data

3 Answers3