php querystring处理，页面跳转

以下代码用来实现带参数跳转

<?php
function removeFromQueryStringByKey($queryString,$key){
    $queryString = preg_replace("/$key.*&/","", $queryString);
    $queryString = preg_replace("/&$key=.*/", "", $queryString);
    return $queryString;
}
function getQueryStringArr($s){
    $result = array();
    if ($s != ""){
        $array = explode("&", $s);
        foreach ($array as $item){
            $I = explode("=", $item);
            $result[$I[0]] = $I[1];
        }
    }
    return $result;
}

function mergeQueryString($currentQueryString,$newQueryString){
    $currentArr = getQueryStringArr($currentQueryString);
    $newArr = getQueryStringArr($newQueryString);
    
    $result = array_replace($currentArr, $newArr);
    return $result;
}

function redirect($location,$currentQueryString,$newQueryString){
    if($location == ""){
        $location = "/index.php";
    }
    $queryString = "";
    $queryStringArr = mergeQueryString($currentQueryString, $newQueryString);
    if (!empty($queryStringArr)){
        foreach ($queryStringArr as $key => $value){
            $queryString .= "&". $key.'='.$value;
        }
        $queryString = substr_replace($queryString, "?", 0, 1);
    }
    header("location:".$location.$queryString);
}

?>

实例：

1、删除querystring的关键字

removeFromQueryStringByKey（"a=2&b=3","a");

结果：b=3

2、带参数跳转

redirect("/index.php","a=2&b=3","b=4");

结果：跳转到 /index.php?a=2&b=4

redirect("/index.php","","")

结果：跳转到 /index.php

redirect("/index.php","a=2&b=3","");

结果：跳转到 /index.php?a=2&b=3

redirect("/index.php","","b=4");

结果：跳转到 /index.php?b=4