php算法看不懂，请高手逐句给解释下吧！急急
$MM_paramName = "";?
// *** Go To Record and Move To Record: create strings for maintaining URL and Form parameters
// create the list of parameters which should not be maintained
$MM_removeList = "&index=";
if ($MM_paramName != "") $MM_removeList .= "&".strtolower($MM_paramName)."=";
$MM_keepURL="";
$MM_keepForm="";
$MM_keepBoth="";
$MM_keepNone="";
// add the URL parameters to the MM_keepURL string
reset ($HTTP_GET_VARS);
while (list ($key, $val) = each ($HTTP_GET_VARS)) {
$nextItem = "&".strtolower($key)."=";
if (!stristr($MM_removeList, $nextItem)) {
$MM_keepURL .= "&".$key."=".urlencode($val);
}
}
// add the URL parameters to the MM_keepURL string
if(isset($HTTP_POST_VARS)){
reset ($HTTP_POST_VARS);
while (list ($key, $val) = each ($HTTP_POST_VARS)) {
$nextItem = "&".strtolower($key)."=";
if (!stristr($MM_removeList, $nextItem)) {
$MM_keepForm .= "&".$key."=".urlencode($val);
}
}
}
// create the Form + URL string and remove the intial '&' from each of the strings
$MM_keepBoth = $MM_keepURL."&".$MM_keepForm;
if (strlen($MM_keepBoth) > 0) $MM_keepBoth = substr($MM_keepBoth, 1);
if (strlen($MM_keepURL) > 0) $MM_keepURL = substr($MM_keepURL, 1);
if (strlen($MM_keepForm) > 0) $MM_keepForm = substr($MM_keepForm, 1);
[解决办法]
把GET参数和POST参数重新全部拼接到GET参数里，形成一个URL叫做MM_keepBoth，由于拼接时采取了. &key=val，所以字符串开始多了一个&, 需要substr删掉。
[解决办法]
来试试看。
$MM_paramName = ""; // *** Go To Record and Move To Record: create strings for maintaining URL and Form parameters// create the list of parameters which should not be maintained$MM_removeList = "&index=";if ($MM_paramName != "") $MM_removeList .= "&".strtolower($MM_paramName)."="; $MM_keepURL="";$MM_keepForm="";$MM_keepBoth="";$MM_keepNone="";// add the URL parameters to the MM_keepURL stringreset ($HTTP_GET_VARS); //$HTTP_GET_VARS等价于$_GET。早起的php3/4版本都是用$HTTP_GET_VARS，不过到了后来版本$HTTP_GET_VARS被弃用了。改用$_GET 了。while (list ($key, $val) = each ($HTTP_GET_VARS)) { //遍历数组每项，键=$key,值=$val$nextItem = "&".strtolower($key)."=";if (!stristr($MM_removeList, $nextItem)) { //如果MM_removeList中不存在$nextItem$MM_keepURL .= "&".$key."=".urlencode($val); //连接字符串}}// add the URL parameters to the MM_keepURL stringif(isset($HTTP_POST_VARS)){ //$HTTP_POST_VARS同$HTTP_GET_VARSreset ($HTTP_POST_VARS); //重置$HTTP_POST_VARS,使其指针回到0while (list ($key, $val) = each ($HTTP_POST_VARS)) { //遍历，同上$nextItem = "&".strtolower($key)."="; //连接字符串if (!stristr($MM_removeList, $nextItem)) { //同上$MM_keepForm .= "&".$key."=".urlencode($val); //同上}}}// create the Form + URL string and remove the intial '&' from each of the strings$MM_keepBoth = $MM_keepURL."&".$MM_keepForm;if (strlen($MM_keepBoth) > 0) $MM_keepBoth = substr($MM_keepBoth, 1); //如果$MM_keepBoth字节长度大于0，则从1字节位置截取到末尾if (strlen($MM_keepURL) > 0) $MM_keepURL = substr($MM_keepURL, 1); //类似上面if (strlen($MM_keepForm) > 0) $MM_keepForm = substr($MM_keepForm, 1); //类似上面