Question

我在JavaScript中有一个多维数组，其中包含基本的用户名和将要散列的密码。目前，当调用检查凭据的功能时，forEach将仅检查最后一个数组。

const titleText = document.getElementById('loginText');
const usernameField = document.getElementById('usernameField');
const passwordField = document.getElementById('passwordField');

const usernames = [['guido','password'],['ben','test']];

function checkCreds() {
    titleText.textContent = ">> Checking login";

    usernames.forEach(element => {
        if (element[0] === usernameField.value) {

            if (element[1] === passwordField.value) {

                titleText.textContent = '>> Login Valid';
                window.location = "dashboard.html";

            } else {
                titleText.textContent = '>> Password incorrect';
            };
        } else {
            titleText.textContent = '>> Login incorrect';
        };
    });
};

在这里，当我输入凭据guido和password时，会说登录不正确。但是当我键入ben和test时，它将照常进行。如果有人对为什么这种方法行不通或有更好的代码有想法，请放弃答案。正如我说的那样，它将在工作时被散列，加盐，而不是文件中的所有内容。

Answer 1

问题似乎是您没有中断循环，因此实际上您正在检查数组中的所有元素，但最后一个元素是要粘贴的元素。尝试从循环中刹车，类似这样；

const titleText = document.getElementById('loginText');
const usernameField = document.getElementById('usernameField');
const passwordField = document.getElementById('passwordField');

const usernames = [
  ['guido', 'password'],
  ['ben', 'test']
];

function checkCreds() {
  titleText.textContent = ">> Checking login";

  // instead of using Array.forEach use a standard for loop, this allows you to
  // break out of the loop and return. 
  for(let i = 0; i < usernames.length; i++){
    if (usernames[i][0] === usernameField.value){
      if (usernames[i][1] === passwordField.value){
        // show that the login was successful
        titleText.textContent = '>> Login Valid';
        // redirect to the dashboard
        window.location = 'dashboard.html';
        // just return here, there is no need to break out of the loop,
        // returning will end the execution of this function.
        return;
      }
    }
  }
  
  // display the error to the user, we don't want to indicate if the 
  // password or the username were invalid because that tells an attacker
  // they have the correct user name.
  // We also don't have to check a flag because a valid login will result
  // in this code never being hit
    titleText.textContent = '>> Login incorrect';
};

编辑：

根据本·韦斯特（Ben West）的信息，我更新了解决方案，以使用标准的for循环以允许脱离循环。

多维javascript数组，仅会影响forEach

1 个答案: