PHP note: For Loop Performance

About a year ago I started to writing code “BUT NOT JUST FOR WRITING IT”, I focused on to trying to fully understand what I’m about to write, in the whole software life cycle and I was giving attention to the performance, speed, and clean code.

So I was trying to improving my “PHP For Loop”.

I was repeating myself and write for loop on this way below:

$array = [0, 1, 2, 3, 4];

for($i = 0; $i < count($array); $i++) {
      print_r ($i);
      echo '<br/>';
}

The above way of writing for loop is WRONG. Why?

In every loop the Count function is called, and that is code overhead, we have just 5 items in the the array, imagine that we have hundred that will absolutely affect the performance of the script.

Let’s try to improve our loop:

$array = [0, 1, 2, 3, 4];
$j = count($array);
for ($i=0; $i < $j; $i++) {
  print_r ($i);
  echo '<br/>';
}

Let’s calculate for loop execution time in seconds and do comparison;

The first script: Executed in 4.0531158447266E-6 seconds

The second script: Executed in 3.0994415283203E-6 seconds

Those notes is about small scripts, try to imagine working on large-scale apps or websites. Making attention to these things will improve your code and totally improve your vision as a software developer or web developer.