PHP fill up array holes - php

Question

I've got an array with values stored per year, per week, coming from my database. The result might look like this:
Array
(
[2018] => Array
(
[40] => 1
[41] => 1
[47] => 1
[48] => 1
[52] => 1
)
[2019] => Array
(
[1] => 1
[2] => 1
[3] => 1
[4] => 1
)
)
or
Array
(
[2018] => Array
(
[48] => 1
[49] => 1
)
[2019] => Array
(
[3] => 1
[4] => 1
)
)
As you can see there are weeks without data. I would like to fill up the array, so all weeks are there. Taking the last array as demo, the desired result would be:
Array
(
[2018] => Array
(
[40] => 1
[41] => 1
[42] => 0 < added
[43] => 0 < added
[44] => 0 < added
[45] => 0 < added
[46] => 0 < added
[47] => 1
[48] => 1
[49] => 0 < added
[50] => 0 < added
[51] => 0 < added
[52] => 1
)
[2019] => Array
(
[1] => 1
[2] => 1
[3] => 1
[4] => 1
)
)
Array
(
[2018] => Array
(
[48] => 1
[49] => 1
[50] => 0 < added
[51] => 0 < added
[52] => 0 < added
)
[2019] => Array
(
[1] => 1
[2] =>
[3] => 1
[4] => 1
)
)
So, the arrays should:
fill up holes between two (not consecutively) numbers
fill up the year array until the end if there is a next year
fill up the first weeks of a new year if there is a previous year and no data in the first week
How can I achieve this?

Answer 1

I think the most efficient way is to use the union operator. This should do it:
<?php
$data = array(
"2018"=> array(
"40" => 1,
"41" => 1,
"47" => 1,
"48" => 1,
"52" => 1
),
"2019"=> array(
"1" => 1,
"2" => 1,
"6" => 1,
"7" => 1
)
);
foreach($data as $year=>$array){
$keys = array_keys($array);
$min = min($keys); $max = 52;
if(!isset($data[$year+1])){
$max = max($keys);
}
$data[$year] = $data[$year] + array_fill($min,$max-$min+1, 0);
ksort($data[$year]);
}
print_r($data);
?>
Output:
Array
(
[2018] => Array
(
[40] => 1
[41] => 1
[42] => 0
[43] => 0
[44] => 0
[45] => 0
[46] => 0
[47] => 1
[48] => 1
[49] => 0
[50] => 0
[51] => 0
[52] => 1
)
[2019] => Array
(
[1] => 1
[2] => 1
[3] => 0
[4] => 0
[5] => 0
[6] => 1
[7] => 1
)
)

Answer 2

You can use a set of array functions such as array_fill() and array_replace() to achieve this.
See comments for the explanation
$array = [
'2018' => [
'40' => 1,
'41' => 1,
'47' => 1,
'48' => 1,
'52' => 1
],
'2019' => [
'3' => 1,
'4' => 1
],
];
$result = []; // initialize result array
$years = array_keys($array); // Get given years
$first_year = min($years); // Get first year
$last_year = max($years); // Get last year
foreach ($array as $year => $value) { // Loop thru each year array
$weeks = array_keys($value); // Get weeks
$start = 1; // Set first week
$weeknum = 52; // Set number of weeks
if ($year === $first_year) { // If first year, change number of weeks
$start = min($weeks);
$weeknum -= $start - 1; // number of weeks is 52 - the first week number - 1
}
if ($year === $last_year) { // If last year, change number of weeks to last given week
$weeknum = max($weeks); // Weeks will be 1 - last given week
}
$result[$year] = array_replace(array_fill($start, $weeknum, 0), $value);
}
var_dump($result);
The first goal of this is to fill an array base on the year.
If first year, create array with first given week to week 52
If last year, create array with week 1 to last given week
If somewhere in the middle, create array with week 1 to week 52
Then replace with your existing data array with same keys