php for循环语法：如何强加多个条件

Question

For a daily calendar application, I want to print out the hours of the day from nine in the morning to eight at night. I am using the following syntax which works up through 12. However, then I want to restart the numbering on 1 and have it continue to 8. I know this could be done in a more complicated way with multiple if then expressions and so forth but hoping there is a clean way to do it with one elegant expression. This is partly because there is a database query in the midst of this that I would like to write out only once. Here is basic code:

PHP
//following works up to 12
for($hourofday = 9; $hourofday <= 12; $hourofday++): 

//I want to do something like following but the following does not work.

//for($hourofday = 9; $hourofday <= 12 || $hourofday >=1 && $hourofday <=8); $hourofday++): 
    $output.= $hourofday.':00';
//This is where dbase is queried for events and there is formatting so it looks like a calendar

endfor

Thanks for any suggestions!

Answer 1

You could do this:

for($hourofday=9; $hourofday <= 20; $hourofday++)
{
    if($hourofday > 12)
        $output .= $hourofday - 12 . ':00';
    else
        $output .= $hourofday . ':00';
}

or the shorter but harder to read way:

for($hourofday=9; $hourofday <= 20; $hourofday++)
{
    $output .= ($hourofday - ($hourofday > 12 ? 12 : 0)) .':00 ';
}