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POMemory consumption on an iteration script
 

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    <p>I have a script written in PHP and the same script written in Javascript.<br/> It iterates a million times and on each time strips a string into an array and assigns the first array item into a new variable.</p> <p>The PHP is:</p> <pre><code>class First { public function Iterate() { $count = 1000000; $test_string = ''; $test_array = ''; $first_word = ''; for($i=1; $i &lt;= $count; $i++){ $test_string = 'This is a test string'; //could use explode but no explode in js $test_array = split(" ", $test_string); $first_word = $test_array[0]; } } } $first = new First(); $first-&gt;Iterate(); </code></pre> <p>And the Javascript is:</p> <pre><code>function First() { this.Iterate = function() { count = 1000000; test_string = ''; test_array = ''; first_word = ''; for(var i=1;i &lt;= count; i++){ test_string = 'This is a test string'; test_array = test_string.split(" "); first_word = test_array[0]; } } } first = new First(); first.Iterate(); </code></pre> <p>I run PHP with PHP-CLI 5.3.10 and the Javascript with node v0.6.12.<br/></p> <p>For PHP I use 'memory_get_usage()' and for Javascript I use 'process.memoryUsage()'. I run them at the start of the script, then at the end, then minus end with start and finally convert the number of bytes into mb.</p> <p>The PHP uses 0.00065 mb of memory whereas Javascript uses 0.25 mb however PHP takes 4 secs and Javascript takes 0.71 secs. I have run the results on 2 different machines.<br/> </p> <p>Does anybody know why the Javascript memory usage would be so much higher than the PHP's (despite the fact that the Javascript is executed so much faster)?</p> <p>The only explanation I could come up with was the V8's nature to use Hidden classes improves speed but increases memory consumption.</p>
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    1. USKingCrunch
    1. USCraig Taub
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    1. COjust a note: the scripts are not the same. the vars inside php function are private, in js are globals.
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      1. USLuca Rainone
    2. COYour test examples aren't as similar as they could be. In the JavaScript You should apply your Iterate method as part of First's prototype object... that way you aren't recreating the method on each execution (which is closer to how php behaves).
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      1. USPebbl
    3. CO@pebbl thanks. Something like First.prototype.Iterate = function()
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      1. USCraig Taub
 

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