Javascript：获取url键值对，修改url键对应的值

getKeyValueFromUrl.js

/*获取url键值对*/
function getParamsFromUrl() {
   var url = decodeURI(location.search); //获取url中"?"符后的字串
   var params = new Object();
   if (url.indexOf("?") != -1) {
      var str = url.substr(1);
      const strs = str.split("&");
      for(var i = 0; i < strs.length; i ++) {
         params[strs[i].split("=")[0]] = unescape(strs[i].split("=")[1]);
      }
   }
   return params;
}

/*
* url 目标url
* arg 需要替换的参数名称
* arg_val 替换后的参数的值
* return url 参数替换后的url
*/
function changeURLArg(url,arg,arg_val){
	var pattern=arg+'=([^&]*)';
	var replaceText=arg+'='+arg_val;
	if(url.match(pattern)){
		var tmp='/('+ arg+'=)([^&]*)/gi';
		tmp=url.replace(eval(tmp),replaceText);
		return tmp;
	}else{
		if(url.match('[\?]')){
			return url+'&'+replaceText;
		}else{
			return url+'?'+replaceText;
		}
	}
}