How can match two array in php - php

Question

I have two array:
One Array
$workingDays = ['2019-11-01','2019-11-02','2019-11-03','2019-11-04'];
Other Array
$doneWork = array(
array(
'id' => 1,
'date' => '2019-11-01',
'work' => 'done'
),
array(
'id' => 1,
'date' => '2019-11-02',
'work' => 'done'
),
array(
'id' => 1,
'date' => '2019-11-04',
'work' => 'done'
)
);
My Question: How can check which date not exist in $doneWork array

Answer 1

You'd start by extracting the dates from $doneWork using array_map.
$doneWork = [
[
'id' => 1,
'date' => '2019-11-01',
'work' => 'done',
],
[
'id' => 1,
'date' => '2019-11-02',
'work' => 'done',
],
[
'id' => 1,
'date' => '2019-11-04',
'work' => 'done',
],
];
$doneWorkDays = array_map(function ($element) {
return $element['date'];
}, $doneWork);
print_r($doneWorkDays);
Will print:
Array ( [0] => 2019-11-01 [1] => 2019-11-02 [2] => 2019-11-04 )
Then check which elements in $workingDays are not in such array, using array_diff
$diff = array_diff($workingDays, $doneWorkDays);
print_r($diff);
Will print:
Array ( [2] => 2019-11-03 )
Pay attention, the result gives you not only the elements but also their index in the original array. If you don't care about these, use instead:
print_r(array_values($diff));
Why would anyone need such index? Well, perhaps you could need to report not only how many days were missed but also check if two missing elements are adjacent.
(the indexes are relevant only for the array you're comparing against. It doesn't matter in what position they appear in $doneWork )
Edit:
You say you need the results to be in "doneWork" format, which is an associative array with id (always zero), date and work (always 'absent').
Let's say your workin days are now
$workingDays = [
'2019-11-01',
'2019-11-02',
'2019-11-03',
'2019-11-04',
'2019-11-05'
];
So there are two missing days. Again, array map to the rescue:
// from previous answer
$diff = (array_diff($workingDays, $doneWorkDays));
// map each missing date to a doneWork array
$diff_assoc = array_values(
array_map(function($date) {
return [
'id' => 0,
'date' => $date,
'work' => 'absent'
];
},$diff)
);
That will return
Array
(
[0] => Array
(
[id] => 0
[date] => 2019-11-03
[work] => absent
)
[1] => Array
(
[id] => 0
[date] => 2019-11-05
[work] => absent
)
)
Again, note I'm wrapping the result in array_values because you need a plain array as result instead of:
Array
(
[2] => Array
(
[id] => 0
[date] => 2019-11-03
[work] => absent
)
[4] => Array
(
[id] => 0
[date] => 2019-11-05
[work] => absent
)
)

Answer 2

$nonExistingDates = [];
$doneWorkDays = [];
foreach($doneWork as $work) {
$doneWorkDays[] = $work['date'];
}
$nonExistingDates = array_diff($workingDays, $doneWorkDays);
// optional, removes duplicate dates
$nonExistingDates = array_unique($nonExistingDates);