迴圈

1.固定次數
for(起始值;符合條件執行;執行動作)
$sum=0;
for($i=0;$i<=50;$i++) {$sum=$sum+i;} 2.依條件執行迴圈 while(條件){ } do{ }while(條件式) $sum=0; $i=1; while($sum<=10000) { $sum+=$i; $i++; } =>($i-1)

3.配合陣列使用迴圈
foreach(陣列 as 變數){ }
$website[]= "http://www.google.com/";
$website[]= "http://tw.yahoo.com/";
$website[]= "http://maiolong.blogspot.com/";
$website[]= "http://shinjia168.site40.net/";
$str='';
foreach($website as $one)
{
$str .= '' . $one. '
' . "\n";
}

4.foreach(陣列 as 變數=>變數){ }
$website=array("google" =>"http://www.google.com",
"yahoo" =>"http://tw.yahoo.com",
"maiolong"=>"http://maiolong.blogspot.com/",
"shinjia" =>"http://shinjia168.site40.net/");
$str=";
foreach($website as $key=>$one)
{
$str.= '' .$key. '
';
}