JavaScript，如果其他条件

问题描述

我有一个JS if / else问题。我能知道为什么，如果输入正确的用户名和密码，还执行else语句吗？

如果正确，如果用户名和密码正确，则仅执行if语句。两者为何被处决？ 代码如下：

var database = [
  {
    username: "john83reuben",password: "12345"
  },{
    username: "jdominic",{
    username: "johnreuban",password: "12345"
  }
];

newsFeed =[
  { username: "john83reuben",timeline: "Psalm 118:19. I will extol the Lord at all times; His praise will always be on my lips"},{ username: "jdominic",timeline: "Psalm 34:1-3. I thank you,Lord,with all my heart; I sing praise to you before the gods."},{ username: "johnreuban",timeline: "Psalm 138: 1-2. I will give thanks to the Lord because of his righteousness;"}
];

function signIn(user,pass){

  for(let i=0; i < database.length ; i++){
    if(database[i].username === user && database[i].password === pass ){
        console.log(newsFeed);

    }else{
      console.log("Error");
    } 

  }
}

var usernamePrompt = prompt("What is your username?");
var passwordPrompt = prompt("What is your password?");

signIn(usernamePrompt,passwordPrompt);

解决方法

您正在检查database var的整个列表，当它与不具有正确凭据的项目匹配时，它将执行else情况，以避免在您使用时打破循环找到正确的一个

,

使用Array.prototype.some方法来确定您的用户/密码是否至少匹配一次。

var result = database.some(item => {
   
    return item.userName === user && item.password === pass

})

console.log(result)