PHP Concatenate Zero to date POST value - php

Question

I need to add a zero to the date value that is posted as the MySQL date value will be used as a directory path to show added photos. Currently the directory is saved as 2012-2-5 and the MySQL entry is 2012-02-05.
I have tried the following, however it doesn't seem to be working:
$dates = array($_POST['photos_year'], $_POST['photos_month'], $_POST['photos_day']);
foreach($dates as $date) {
if (strlen($date) == 1) {
$date = '0' . $date;
}
}
$photos->date = $dates[0] . "-" . $dates[1] . "-" . $dates[2];
I am using a for loop to create the date form, it might be easier for me to edit this however I haven't had any success:
<select name="photos_month" id="photos_month" tabindex="3">
<option value ="">- Month -</option>
<?php
for($date=01;$date<=12;$date++) {
if (isset($photos) && $date==$month) {
echo "<option value='".$date."' selected='selected'>".$date."</option>";
} else {
echo "<option value='".$date."'>".$date."</option>";
}
}
?>
</select>

Answer 1

You need to update the foreach to be
foreach ($dates as &$date)
Currently, $date is a new symbol and will not overwrite the value. That should fix it, but it may be nice to have the correct strings in the options too. You can use str_pad to do that.

Answer 2

When doing a foreach, the element variable $date is a new variable, a copy of the value from the array. You should use a key and update the original array.
foreach($dates as $key => $date) {
if (strlen($date) == 1) {
$dates[$key] = '0' . $date;
}
}
Also, you're running that code on the year, you don't want to be adding a zero to the year, only the month and day.

Answer 3

You could make it a little simpler by just using sprintf with a format string;
$photos_year = '2012';
$photos_month = '2';
$photos_day = '5';
$result = sprintf("%4d-%02d-%02d", $photos_year, $photos_month, $photos_day);
// $result = '2012-02-05'

Answer 4

Check out the string pad function http://php.net/manual/en/function.str-pad.php
Along with the array map function http://php.net/manual/en/function.array-map.php
Using these two together would allow for you to go through each part of the date(array_map) and pad the value with a 0 (using str_pad)
Code would look something like this
$dates = array_map("padString",$dates);
function padString($string) {
return str_pad($string,2,"0",STR_PAD_LEFT);
}
print_r($dates);
//Gives you Array ( [0] => 2012 [1] => 02 [2] => 05 )

Answer 5

use sprintf()
For example:
$date = sprintf('%02d', $_POST['photos_day']);