Question

过去几个月我一直在使用以下代码，这些代码从预定义的日期开始经过几个月的时间，直到达到今天的日期。

use Date::Pcalc qw(:all);

$startDay = 1;
$startMonth = '4';
$startYear = '2009';

$dateToday = `date +%Y-%m-%d`;
($yt,$mt,$dt) = split(/\-/,$dateToday);

while ($endMonth <= $mt || $startYear < $yt ) {

if ($startMonth eq '12') {
    $endMonth = 1;
    $endYear = $startYear + 1;
  } else {
    $endMonth = $startMonth + 1;
    $endYear = $startYear;
  }

  if ($startMonth eq '12') {
    $endYear = $startYear + 1;
  }

  ($meYear,$meMonth,$meDay) = Add_Delta_Days($endYear,$endMonth,$startDay,-1);
  $endOfMonth = "$meYear-$meMonth-$meDay";
  $monthText = Month_to_Text($startMonth);

  $startDate = "$startYear-$startMonth-1";
  $endDate = "$endYear-$endMonth-1";

print "$startDate - $endDate\n";

if ($startMonth eq '12') {
    $startMonth = 1;
    $startYear++;
  } else {
    $startMonth++
  }

}

这在过去几个月一直很有效，但我已经意识到现在在12月，由于$ endmonth永远不会更大$ mt（12），这会导致无限循环。

我无法找出任何替代方法。我觉得我应该能够相对容易地解决这个问题，但我似乎有严重的“开发人员阻止”

提前感谢任何可以提供协助的人。

Answer 1

my $date = DateTime->new(
   time_zone => 'local',
   year      => $startYear,
   month     => $startMonth,
   day       => 1,
);

my $today = DateTime->today(time_zone => 'local');

while ($date <= $today) {
   say $date->ymd('-');
   $date->add( months => 1 );
}

Answer 2

我认为您的代码存在一些问题。但是让我们来看看第12个问题的第一个问题，这个问题导致了这个语句中的循环：

    while ($endMonth <= $mt || $startYear < $yt ) {

一旦你有了当前的日期，年月和日，你应该做的就是这样。您会注意到其他人建议了获取当前日期的不同方法您应该采纳这个建议。但是，如果您有日期，则应采用以下代码：

    ($yt,$mt,$dt) = split(/\-/,$dateToday);
    # the line below will create a date like 201212 (yyyy mm) but if the month is a 1 digit month it will place a 0 in front of it to ensure your yymm variable always holds 6 characters in the format of yyyy mm - ok
    my $yymm = $yt . ${\(length($mt) == 1 ? '0' : '')} . $mt;
    # Now lets check the end date against the yymm
    # initialise end date as end_yymm - again it inserts a 0 for single digit month
    my $end_yymm = $startyear . ${\(length($startMonth) == 1 ? '0' : '')} . $startMonth;
    # the above should get the date as '200904' from your code provide
    # the while will check end_yymm like 200904 < 201212 - yes it is...
    ## the end_yymm will keep getting incremented each month and so will the year component at the end of each year until it reaches 201212
    ## then the question 201212 < 201212 will cause the while to end
    ## If you want it go into 201301 then say while ($end_yymm <= $yymm) {
    ## Hope you get the picture
    while ($end_yymm < $yymm) {

    if ($startMonth eq '12') {
        $endMonth = 1;
        $endYear = $startYear + 1;
    } else {
      $endMonth = $startMonth + 1;
      $endYear = $startYear;
    }

    ## Now this one seems to be repeating the endYear calculation as above - to me it seems redundant - maybe get rid of it
    if ($startMonth eq '12') {
       $endYear = $startYear + 1;
    }        

    ## Now that you have the end year and month incremented setup the end_yymm variable again to be picked up in the while statement:
    $end_yymm = $startyear . ${\(length($startMonth) == 1 ? '0' : '')} . $startMonth;

     # ...... carry on with the rest of your code

    } # end the while loop

那应该这样做。

一切顺利

Perl - 每月增量循环

2 个答案: