PHP Array

<?php
//Hash Array 內存佔用大
$memory_start = memory_get_usage();
$test = array();
for($i=200000;$i>=0;$i--){
    $test[$i] = 1;
}
echo memory_get_usage() - $memory_start,"bytes\n";
//9437264bytes


//Packed Array 內存佔用小
$memory_start = memory_get_usage();
$test = array();
for($i=0;$i<=200000;$i++){
    $test[$i] = 1;
}
echo memory_get_usage() - $memory_start,"bytes\n";
//8392784bytes

?>