Storing the results of a function in a variable and referencing the
variable will almost always be faster, this should be no surprise
because instead of executing the function PHP just has to return the
variable's value.
In #1 since you only call the function once the function is only
executed once, in a loop it is executed once for each loop iteration.
Jason
On Sat, 2003-03-15 at 21:25, Don Read wrote:
> On 15-Mar-2003 CF High wrote:
> > Hey all.
> >
> > Quick question:
> >
> > If I have a function that, say, prints out the months in a year, and I
> > call
> > that function within a 10 cycle loop, which of the following is faster:
> >
> > 1) Have function months() return months as a string; set var
> > string_months = months() outside of the loop; then echo string_months
> > within
> > the loop
> >
> > -- OR
> >
> > 2) Just call months() for each iteration through the loop
> >
> > I'm not sure how PHP interprets option number 1.
> >
> > Guidance for the clueless much appreciated...........
> >
>
> Easy enuff to test:
>
> <?php
>
> function getmicrotime(){
> list($usec, $sec) = explode(" ",microtime());
> return ((float)$usec + (float)$sec);
> }
>
> $time_start = getmicrotime();
> for ($m=1; $m <11; $m++) {
> echo date('F', strtotime("2003-$m-1")), '<br>';
> }
> echo '<P>A: ', getmicrotime() - $time_start , '<P>';
>
> $time_start = getmicrotime();
> for ($m=1; $m <11; $m++) {
> $str[]=date('F', strtotime("2003-$m-1"));
> }
> echo implode('<br>',$str);
> echo '<P>B: ', getmicrotime() - $time_start , '<P>';
>
> unset($str);
> $time_start = getmicrotime();
> for ($m=1; $m <11; $m++) {
> $str[]=date('F', strtotime("2003-$m-1"));
> }
>
> while (list(,$v)= each($str)) {
> echo $v, '<br>';
> }
> echo '<P>C: ', getmicrotime() - $time_start , '<P>';
>
> ?>
>
> On my machine I get numbers like:
> A: 0.000907063484192
> B: 0.000651001930237
> C: 0.000686049461365
>
> The function call within the loop is slower (contrary to what I
> expected), the real question is how much effort do you want to expend to
> save 2-3 micro-seconds?
>
> Regards,
> --
> Don Read [EMAIL PROTECTED]
> -- It's always darkest before the dawn. So if you are going to
> steal the neighbor's newspaper, that's the time to do it.
--
Jason Sheets <[EMAIL PROTECTED]>
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