Check same value in array - php

Question

I have the following array:
$teams = [["id" => 1, "address" => "A1"],["id" => 2, "address" => "A1"],["id" => 3, "address" => "A2"]];
How can I check and get the teams with the same address? My output should be Team ID 1 and 2? Consider that I cannot use hard coded address. The data is dynamic and is coming from the database.
In php, laravel.
Thank you in advance!

Answer 1

Another way to do this is to use array_column() and array_count_values(). Then use array_filter() to remove elements with no duplicates:
$teams = [
["id" => 1, "address" => "A1"],
["id" => 2, "address" => "A1"] ,
["id" => 3, "address" => "A2"]
];
$dups = array_count_values(array_column($teams, 'address'));
$teams = array_filter($teams, function($item) use($dups) {
return $dups[$item['address']] > 1;
});
print_r($teams);
Outputs (reformatted):
Array
(
[0] => Array([id] => 1, [address] => A1)
[1] => Array([id] => 2, [address] => A1)
)

Answer 2

First you need to group by their address and then you can use array_filter() to truncate your array based on criteria:
<?php
$teams = [["id" => 1, "address" => "A1"],["id" => 2, "address" => "A1"],["id" => 3, "address" => "A2"]];
// Set a new array
$filtered = [];
// Loop the teams
foreach($teams as $v)
{
// Group the teams into their respective addresses
$filtered[$v['address']][] = $v;
}
// Filter out any address with 1 or fewer teams
$filtered = array_filter($filtered, function($v){
return count($v) > 1;
});
print_r($filtered);
// Now you can loop $filtered and display whatever you want
Output:
Array
(
[A1] => Array
(
[0] => Array
(
[id] => 1
[address] => A1
)
[1] => Array
(
[id] => 2
[address] => A1
)
)
)

Answer 3

Go through the array, remember which addresses are used by which team. When there is more than one team stored at a key (address), you found a duplicate:
<?php
$teams = [
["id" => 1, "address" => "A1"]
,["id" => 2, "address" => "A1"]
,["id" => 3, "address" => "A2"]
];
function findDuplicates($teams) {
$addresses = [];
foreach ($teams as $team) {
if (!isset($addresses[$team["address"]])) {
$addresses[$team["address"]] = [];
}
$addresses[$team["address"]][] = $team["id"];
}
foreach ($addresses as $address => $teamsHere) {
if (count($teamsHere) > 1) {
echo "Teams with same address (" . $address . "): " . join(",", $teamsHere) . "\n";
}
}
}
findDuplicates($teams);
Try it online!
Edit: a less "clunky" approach, using array_* functions:
<?php
$teams = [
["id" => 1, "address" => "A1"]
,["id" => 2, "address" => "A1"]
,["id" => 3, "address" => "A2"]
];
function findDuplicates($teams) {
$addresses = array_column($teams, "address");
$counts = array_count_values($addresses);
return array_filter($teams, function($team) use ($counts) { return $counts[$team["address"]] > 1; });
}
print_r(findDuplicates($teams));
Try it online!