Using count directly in loops/cycles is wrong (PHP)
Count is a PHP command that … counts all elements in an array, or properties in an object.
But when you need to use it in loops, first assign a new variable then use the variable in the loop. For example :
<?php
//size of $arr ~ 2000 elements
//WRONG variant (Time exec ~ 19 sec)
for($i=0;$i<count($arr);$i++)
{
//... loop code here ...
}
//RIGHT variant(Time exec ~ 0.2 sec)
$arr_size=count($arr);
for($i=0;$i<$arr_size;$i++)
{
//... loop code here ...
} ?>
Another example :
<?php
for ($i=0; $i<10000; $i++) {
$arr[] = $i;
}
$time11 = microtime_float();
$bf = "";
for ($i=0; $i<count($arr); $i++) {
$bf .= $arr[$i]."\n";
}
$time12 = microtime_float();
$time1 = $time12 - $time11;
print "First: ".$time1."\n";
$time21 = microtime_float();
$l = count($arr);
for ($i=0; $i<$l; $i++) {
$bf .= $arr[$i]."\n";
}
$time22 = microtime_float();
$time2 = $time22 - $time21;
print "Second: ".$time2."\n";
?>
The output from the code above is (when run many times):
First: 0.13001585006714
Second: 0.099159002304077
First: 0.12128901481628
Second: 0.079941987991333
First: 0.18690299987793
Second: 0.13346600532532
As you can see, the second method (which doesnt use count() directly in the loop) is faster than the first method (which uses count() directly in the loop).
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