Question

我有两个字符串： str1是具有属性

的控制器的URL

str1 = /Controller/Action?tableid=212&id=&someOtherVal=false

和str2是在字段中更改后，'id ='为str1后应添加的id值。

如何在str1中'id ='之后添加此ID，例如'123'？

Answer 1

我希望下面的代码段是您所期待的

var str1 = "/Controller/Action?tableid=212&id=&someOtherVal=false";
// location.protocol + location.hostname is just to complete the URL
var urltoedit = new URL(location.protocol + location.hostname + str1);
var str2 = 123;
// check if id has value or you can modify if your condition
if(urltoedit.searchParams.get("id")=="")
{
     urltoedit.searchParams.set("id",str2);
}
// valtoset is what you need
var valtoset = urltoedit.pathname+urltoedit.search;

Answer 2

您只需使用替换：

var val = '123';
var str1 = '/Controller/Action?tableid=212&id=&someOtherVal=false'.replace('&id=','&id='+val);

console.log(str1);

如果你确定{＆amp; id之后的&将会存在，那么这将是完美的。此外，您不能简单地使用replace('id=','&id=123');，因为您看到字符串tableid=将与此匹配，123的值tableid将替换为tableid=123，它变为id }

对于备份，如果您认为var val = '123'; var str1 = '/Controller/Action?tableid=212&id=&someOtherVal=false'.replace('&id=','&id='+val).replace('?id=','&id='+val); console.log(str1);将位于查询字符串的开头，那么您可以执行此操作：

firebase.auth().onAuthStateChanged(function(user) {
  if (user) {
    // User is signed in.
    var displayName = user.displayName;
    var email = user.email;
    var photoURL = user.photoURL;
} else {
    // User is not logged in, redirect to where you need to.
      console.log("Logged out");
}

Answer 3

如果id是第一个或最后一个参数，并且id已经有值，则需要处理。这是解决方案：

var url = "/Controller/Action?tableid=212&id=rrr&someOtherVal=false";
var parameterName = "id";
var value = "123";

function replaceParameterValueInUrl(url, parameter, value){
    var parameterStart1 = "&" + parameter + "=";
    var parameterStart2 = "?" + parameter + "=";

    //Is first parameter in URL?
    var parameterStart = url.indexOf(parameterStart1) === -1 ? parameterStart2 : parameterStart1;

    var parameterEnd = "&"; 

    var startIndex = url.indexOf(parameterStart);
    var endIndex = url.substring(startIndex + parameterStart.length).indexOf(parameterEnd);

    //Is last parameter of URL?
    if(endIndex === -1) endIndex = 0;

    var searchIndex = startIndex + endIndex;
    return url.substring(0, startIndex + parameterStart.length) + value + (endIndex === 0 ? "" : url.substring(searchIndex + parameterStart.length));
}


//Usage:
var replaced = replaceParameterValueInUrl(url, parameterName, value);

在某些子字符串后将字符串X添加到字符串Y.

3 个答案: