php若干单维数组遍历方法的比较

<?php 
//a 
$arr=array(&#39;a&#39;=>&#39;abc&#39;,&#39;b&#39;=>123,&#39;c&#39;=>true); 
//b 
//$arr=range(&#39;a&#39;,&#39;d&#39;); 
//1 
for($i=0;$i<sizeof($arr);$i++) 
echo $arr[$i].&#39;, &#39;; 
echo &#39;<br />&#39;; 
//2 
foreach($arr as $key) 
echo "$key, "; 
echo &#39;<br />&#39;; 
//3 
foreach($arr as $key=>$val) 
echo "$key-$val, "; 
echo &#39;<br />&#39;; 
//4 
reset($arr); 
while($item=each($arr)){ 
echo $item[&#39;key&#39;].&#39;-&#39;.$item[&#39;value&#39;].&#39;, &#39;; 
} 
echo &#39;<br />&#39;; 
//5 
reset($arr); 
while(list($key,$val)=each($arr)){ 
echo "$key-$val, "; 
} 
echo &#39;<br />&#39;; 
?>