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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By moschos

This is me :)

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