Manipulating arrays of dates in PHP - php

Question

I'm having a lot of difficulty approaching a piece of code in PHP. I have an array of dates and values, for example
dates = (2014-12-01,2014-12-02,2014-12-08,2014-12-09,2014-12-10,2014-12-11)
values = (5,3,7,8,9,2)
You'll note that 12/01 is a Monday, as is 12/08. I'd like to form 4 arrays from these two arrays:
monday = (5,7)
tuesday = (3,8)
wednesday = (0,9)
thursday = (0,2)
You'll note that the arrays are formed by grabbing the values associated with the days of the week. However, in the case that a Wednesday date exists, for example, but the prior Tuesday does not, then the array should have a "0". In other words, the 4 arrays should all be the same length.
Can anyone help me write code in PHP to achieve this? Thanks in advance!
NOTE: So far, I have only determined how to find the day of the week from a date: date('l', strtotime("2014-12-08")); I really can't figure out the general algorithm to solve this.

Answer 1

$dates = array( '2014-12-01','2014-12-02','2014-12-08','2014-12-09',
'2014-12-10','2014-12-11' );
$values = array( 5, 3, 7, 8, 9, 2 );
$date = strtotime(min($dates));
$stop = strtotime(max($dates));
$dates = array_flip($dates);
$out = array();
while($date <= $stop)
{
$tmp = date('Y-m-d', $date);
$out[date('l', $date)][] = isset($dates[$tmp]) && isset($values[$dates[$tmp]]) ?
$values[$dates[$tmp]] : 0;
$date = strtotime('+1 day', $date);
}
print_r($out);
Result:
Array
(
[Monday] => Array
(
[0] => 5
[1] => 7
)
[Tuesday] => Array
(
[0] => 3
[1] => 8
)
[Wednesday] => Array
(
[0] => 0
[1] => 9
)
[Thursday] => Array
(
[0] => 0
[1] => 2
)
[Friday] => Array
(
[0] => 0
)
[Saturday] => Array
(
[0] => 0
)
[Sunday] => Array
(
[0] => 0
)
)
ps: how can I get the an array of all the dates included in the "dates" array associated with only all the Mondays?
Modify the code as, for example:
$tmp = date('Y-m-d', $date);
$exists = isset($dates[$tmp]) && isset($values[$dates[$tmp]]);
$out[date('l', $date)]['numbers'][] = $exists ? $values[$dates[$tmp]] : 0;
if ($exists) $out[date('l', $date)]['dates'][] = $tmp;
$date = strtotime('+1 day', $date);
You'll get an output as (example for monday)
[Monday] => Array
(
[numbers] => Array
(
[0] => 5
[1] => 7
)
[dates] => Array
(
[0] => 2014-12-01
[1] => 2014-12-08
)
)

Answer 2

Might be a better way to get the 0s in there without another loop but I'm headed out:
foreach($dates as $key => $val) {
$day = date('l', strtotime($val));
$result[$day][] = $values[$key];
}
foreach($result as &$val) {
if(count($val) == 1) {
array_unshift($val, 0);
}
}
print_r($result);