PHP Calculation Program Execution time

How does PHP calculate program execution time? This paper mainly introduces the method of PHP computational program execution time, taking the MD5 function encryption run time as an example to analyze the PHP calculation function running time skills. We hope to help you.

This example describes how PHP calculates the execution time of a function. Share to everyone for your reference. Specific as follows:

We can record the start and end time respectively before and after the program, the two time difference is the execution of the program.

<?php$long_str = "This was a test to see how much time MD5 function takes to execute over this string";//Start timing F Rom Here$start = Microtime (TRUE);//function to TEST$MD5 = MD5 ($long _str), $elapsed = Microtime (True)-$start; echo "that T Ook $elapsed seconds.\n ";? >

The results of the operation are as follows:

That took 7.1525573730469E-6 seconds.

How PHP calculates function execution time and how to get a subtle approach

Get Subtle method function Getmillisecond () {   list ($s 1, $s 2) = explode (' ', Microtime ());   return (float) sprintf ('%.0f ', (Floatval ($s 1) + floatval ($s 2)) * 1000); }

Principle: Record function start time and end time separately, then time difference is function execution

<?php $start _time = Microtime (True); for ($i =1; $i <=1000; $i + +) {echo $i. ' <br> ';} $end _time = Microtime (true); Echo ' Loop execution time is: '. ($end _time-$start _time). ' S ';? >

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