[RESOLVED] floor, intval and time

phpSimon

Hi all

I'm using this code to create minutes and seconds variables from seconds.

$mins = floor($seconds / 60);
$secs = $seconds - ($mins * 60);

This works fine unless $seconds is negative. If $seconds is negative but more than -60 (ie, between 0 and -59), it seems to return both $mins and $secs as zero. Does anyone know a simple chunk of code that will take a $seconds value and return $mins and $secs, but handle negative values correctly too? I've tried intval but that doesn't seem any better.

Thanks

DaveRandom

Not tested this but probably best to inverse it if it is negative, then flip it back after the calc:

$neg = FALSE;
if ($seconds < 0) {
  $neg = TRUE;
  $seconds *= -1;
}
$mins = floor($seconds / 60); 
$secs = $seconds - ($mins * 60);
if ($neg) {
  $secs *= -1;
  $mins *= -1;
}

phpSimon

Wow, that's neat - thanks, I'll try it !

phpSimon

Works really well, thanks again.

I removed:

$secs *= -1;

Because in this case, a single negative for both minutes and seconds is fine.

IE:

-1m -30s becomes -1m 30s.

Thank you again.

cretaceous

use the abs function to get the absolute value

DaveRandom

Cool, never knew that existed.

$i = abs($i);

seems to be about 40% quicker than

$i *= -1;

however the fastest method (on average) seems to be

$i = 0 - $i;

Here is my code for testing that theory...

$tot1 = $tot2 = $tot3 = 0;
$loops = 10;

for ($i = 0; $i < $loops; $i++) {
  $pos = -32.145263;

  $start1 = microtime(TRUE);
  $calc1 = $pos *= -1;
  $end1 = microtime(TRUE);
  $tot1 += ($end1 - $start1);

  $start2 = microtime(TRUE);
  $calc2 = abs($pos);
  $end2 = microtime(TRUE);
  $tot2 += ($end2 - $start2);

  $start3 = microtime(TRUE);
  $calc3 = 0 - $pos;
  $end3 = microtime(TRUE);
  $tot3 += ($end3 - $start3);

}

print ("Average totals:\n\$pos *= -1: ".($tot1 / $loops)."\nabs(\$pos): ".($tot2 / $loops)."\n0 - \$pos: ".($tot3 / $loops)."\n");

...and on my win32 machine that outputs

Average totals:
$pos *= -1: 4.9829483032227E-6
abs($pos): 3.4332275390625E-6
0 - $pos: 2.5272369384766E-6

abs() doesn't flip back to negative, which the other two do...

cretaceous

yeah you still need to do *-1 at the end for the negatives, but thought I'd mention abs anyway!

phpSimon

Glad the thread helped someone else too, and generated more discussion!