How to calculate runtime in PHP

Question

I would like to know how long it takes for a certain function, loop loop, etc... to be executed. I use the function microtime(), but I am a little lost to know exactly what time was spent. And my doubts are as follows:

1- How can I convert microseconds into seconds? So that it becomes somewhat readable and if you have a sense of the time that was spent during execution.

<?php

   $tempoInicial = round(microtime(true) * 1000);

   $var = 100000;

   for ($i=0; $i < $var; $i++) { 
      echo "$i -> ";
   }

   $tempoFinal = round(microtime(true) * 1000);

   $total = $tempoFinal - $tempoInicial;

   echo "Resultado: Tempo inicial: $tempoInicial <br> Tempo final: 
   $tempoFinal <br> Total: $total";

2- Is there any tool or resource available for PHP that can check in real time something like the execution speed of the script, of a function, loop, etc.

Answer 1

Microsecond (Ms) is a multiple of the second, a unit of time, prefixed by the micro (µ) multiplier base patterns, equal to 0.000001 seconds(1 microsecond = 1.0E-6 seconds). So, to get the time in seconds, you must divide by 1000000.

From the PHP 5 you can use microtime at the beginning and end of your code:

<?php
    $inicio = microtime(true);
    sleep(1);
    $fim = microtime(true);
    $tempo = $fim - $inicio;
    printf("Processado em: %0.16f segundos", $tempo/1000000);
?>

See working: https://paiza.io/projects/udZy3WdDvQ4kYrUj7AGSSQ

From the PHP 5.4.0 , there is no need to start the start time, the $_SERVER["REQUEST_TIME_FLOAT"] already owns it:

<?php
    sleep(1);
    $tempo = microtime(true) - $_SERVER["REQUEST_TIME_FLOAT"];
    printf("Processado em: %0.16f segundos", $tempo/1000000);
?>

See Working: https://paiza.io/projects/JhDm9gJcBiFOu7hL_4ydtg

References

Microsecond to Seconds Conversion Calculator

Documentation microtime PHP

How to find php runtime?

Answer 2

Utilize time() instead of microtime()