如何添加邏輯運算符？

Question

我一直在嘗試Codecademy這個問題整天。我做的沒有任何事情似乎有效。

說明： 「添加一些if/else語句，以您的案件檢查，看看一個條件和其他條件是否屬實，還有一個條件或者其他條件是否真實使用& &和||至少。每一次。「

這是我以前輸入的代碼：

var user = prompt("What is your name?").toUpperCase(); 

switch(user) { 
    case 'Sam': 
     console.log("Hi, Sam"); 
     break; 
    case 'John': 
     console.log("Hi, John"); 
     break; 
    case 'Mary': 
     console.log("Hi, Mary"); 
     break; 
    default: 
     console.log("I don't know you. What is your name?"); 
} 

Answer 1

1. .toUpperCase()轉換一個字符串爲大寫字母，所以這將是 'SAM'， '約翰' 等

更改它像這樣：

String.prototype.capitalizeFirstLetter = function() { 
    return this.charAt(0).toUpperCase() + this.slice(1); 
} 

var user = prompt("What is your name?").capitalizeFirstLetter() 

1. 你需要測試什麼條件？

   switch(user) { 
   case 'Sam': 
       if (someCondition || anotherCondition) { 
         // do something 
       } else { // do something 
       } 
       console.log("Hi, Sam"); 
       break; 
   
   case 'John': 
       console.log("Hi, John"); 
       break; 
   
   case 'Mary': 
       console.log("Hi, Mary"); 
       break; 
   
   default: 
       console.log("I don't know you. What is your name?」); 
   } 
   

Answer 2

您的代碼沒有任何if/else語句。怎麼樣這樣的事情：

var user = prompt("What is your name?").toUpperCase(); 

// If user is known, greet him 
if (user === "SAM" || user === "JOHN" || user === "MARY") { 
    console.log("Hi, " + user) 
} 
// Otherwise apologize because we are polite 
else { 
    console.log("Sorry " + user + ", I don't know you."); 
} 

// If user is neither John nor Sam, ask about them 
if (user !== "JOHN" && user !== "SAM") { 
    console.log("By the way, how are John and Sam doing?"); 
}