Why this list just go up to september? - php

Question

I have this code
<?php
$startYear = 2011;
while ($startYear <= date('Y')) {
echo "$startYear <br>";
for ($m=1; $m<=12; $m++) {
$theDate = $startYear . $m;
if ($theDate <= date('Yn')) {
$month = date('F', mktime(0,0,0,$m, 1, $startYear));
echo $month. '<br>';
}
}
$startYear++;
};
?>
because I would like to write a list of the type
2013
January
February
March
April
May
June
July
August
September
October
November
December
until the current year and the present month
but every list of months of every year just goes until september, why?

Answer 1

You have to change your if statement from this:
if ($theDate <= date('Yn')) {
to this:
if ($theDate <= date('Ym')) {
//^ See here the placeholder for month with leading zero
For more information about date() see the manual: http://php.net/manual/en/function.date.php

Answer 2

Because 201410 > 21049. This is what happens when you use date() for date math for which it is not suited.
DateTime() and its related functions are better suited for this:
$startYear = 2011;
$start = (new DateTime())->setDate($startYear,1,1);
$end = (new DateTime())->setDate($startYear,1,1)->modify('+1 year');
$interval = new DateInterval('P1M');
$period = new DatePeriod($start, $interval, $end);
foreach ($period as $dt) {
echo $dt->format('F') . "\n";
}
Demo
If you're using PHP 5.5+ it is a little cleaner
$startYear = 2011;
$start = (new DateTimeImmutable())->setDate($startYear,1,1);
$end = $start->modify('+1 year');
$interval = new DateInterval('P1M');
$period = new DatePeriod($start, $interval, $end);
foreach ($period as $dt) {
echo $dt->format('F') . "\n";
}
Demo

Answer 3

i edited my code to add a leading zero to the variable who will represent the month number, edited the current date from date('Yn') to date('Ym') and works.
<?php
$startYear = 2011;
while ($startYear <= date('Y')) {
echo "$startYear <br>";
for ($m=1; $m<=12; $m++) {
$f = sprintf('%02d', $m);
$theDate = $startYear . $f;
if ($theDate <= date('Ym')) {
$month = date('F', mktime(0,0,0,$f, 1, $startYear));
echo $month. '<br>';
}
}
$startYear++;
};
?>
Thanks for the answer guys.