js获取URL中的参数

function UrlSearch() {
   var name,value;
   var str=location.href; //取得整个地址栏
   var num=str.indexOf("?")
   str=str.substr(num+1); //取得所有参数   stringvar.substr(start [, length ]

   var arr=str.split("&"); //各个参数放到数组里
    console.log(arr)
   for(var i=0;i < arr.length;i++){
        num=arr[i].indexOf("=");
        if(num>0){
             name=arr[i].substring(0,num);
             value=arr[i].substr(num+1);
             this[name]=value;
        }
   }
}

console.log(getQueryString("useless"));
function getQueryString(name) {
    var reg = new RegExp("(^|&)" + name + "=([^&]*)(&|$)", "i");
    var reg_rewrite = new RegExp("(^|/)" + name + "/([^/]*)(/|$)", "i");
    var r = window.location.search.substr(1).match(reg);
    var q = window.location.pathname.substr(1).match(reg_rewrite);
    if(r != null){
        return unescape(r[2]);
    }else if(q != null){
        return unescape(q[2]);
    }else{
        return null;
    }
}

/**
 * 获取指定的URL参数值
 * URL:http://www.quwan.com/index?name=tyler
 * 参数：paramName URL参数
 * 调用方法:getParam("name")
 * 返回值:tyler
 */
function getParam(paramName) {
    paramValue = "", isFound = !1;
    if (this.location.search.indexOf("?") == 0 && this.location.search.indexOf("=") > 1) {
        arrSource = unescape(this.location.search).substring(1, this.location.search.length).split("&"), i = 0;
        while (i < arrSource.length && !isFound) arrSource[i].indexOf("=") > 0 && arrSource[i].split("=")[0].toLowerCase() == paramName.toLowerCase() && (paramValue = arrSource[i].split("=")[1], isFound = !0), i++
    }
    return paramValue == "" && (paramValue = null), paramValue
}