for relation array

<?php

echo "Hello World\n";

$arr = array("a"=>"aaa","b"=>"bbb");

$len = sizeof($arr);
for($i=0;$i<$len;$i++){
   echo key($arr)."=>";
   echo current($arr)."\n";
   next($arr);
}

echo "---------------------\n";

for(reset($arr);$k=key($arr),$v=current($arr);next($arr)){
    echo $k.'=>'.$v."\n";
}