PHP Array - Count Partial Duplicates - php

Question

I have an array of objects.
I want to count the total number of array items where two values are an exact match.
Array
(
[0] => stdClass Object
(
[Job] => stdClass Object
(
[ID] => 123
[Line] => Shirt
[Color] => Blue
)
)
[1] => stdClass Object
(
[Job] => stdClass Object
(
[ID] => 456
[Line] => Jeans
[Color] => Blue
)
)
[2] => stdClass Object
(
[Job] => stdClass Object
(
[ID] => 789
[Line] => Jeans
[Color] => Blue
)
)
)
In this simplified example I want to Count that there are 2 array items that have Blue Jeans.

Answer 1

Probably the best approach is to use an index as one would do inside a database:
<?php
$json = <<<JSON
[
{"Job":{"ID":123,"Line":"Shirt","Color":"Blue"}},
{"Job":{"ID":456,"Line":"Jeans","Color":"Blue"}},
{"Job":{"ID":789,"Line":"Jeans","Color":"Blue"}}
]
JSON;
$data = json_decode($json);
$index = [];
$counter = 0;
array_walk($data, function(\stdClass $entry) use (&$index, &$counter) {
$key = $entry->Job->Line . '|' . $entry->Job->Color;
if (!in_array($key, $index)) {
$index[] = $key;
} else {
$counter++;
}
});
print_r($counter);
The output obviously is:
1

Answer 2

Just use a good old loop.
$count = 0; //Initialize the number of matches to 0
//Loop through each item (obviously)
foreach($array as $item) {
//Check if the required properties match.
//If they do, increment $count by 1
if($item->Job->Line=="Jeans" && $item->Job->Color=="Blue") ++$count;
}
//Do whatever is required with the value of $count

Answer 3

Here is another approach using simple recursion. You can set the number of matches desired, and it will find matches for any property (nothing is fixed). I wrapped it in a class to keep everything contained:
<?php
class MatchFind {
// This can be set to any number of matches desired
const ELEMENTS_TO_FIND = 2;
public static function count ($aObjs) {
// Cannot compare elements unless there are 2
if (sizeof($aObjs) <= 1) {
return 0;
}
// Get the top element from the array
$oTop = array_shift($aObjs);
$aTopProps = (array) $oTop->Job;
// Get the number of matches, moving from end to start,
// removing each match from the array
$iMatchObjs = 0;
for ($n = sizeof($aObjs); $n > 0; $n--) {
$oCompare = $aObjs[$n-1];
$iMatch = 0;
foreach ((array) $oCompare->Job as $sKey => $sValue) {
if (isset($aTopProps[$sKey]) && $aTopProps[$sKey] === $sValue) {
++$iMatch;
}
}
if ($iMatch >= self::ELEMENTS_TO_FIND) {
unset($aObjs[$n-1]);
++$iMatchObjs;
}
}
reset($aObjs);
return ($iMatchObjs + self::count($aObjs));
}
}
// Declare the objects
$aAllObjs = [
(object)[ 'Job' => (object)['ID' => 123,
'Line' => 'Shirt',
'Color' => 'Blue'] ],
(object)[ 'Job' => (object)['ID' => 456,
'Line' => 'Jeans',
'Color' => 'Blue'] ],
(object)[ 'Job' => (object)['ID' => 789,
'Line' => 'Jeans',
'Color' => 'Blue'] ],
];
echo MatchFind::count($aAllObjs);