Codecademy JavaScript 中的控制流编程

Question

这个程序会给出三个路线选择，然后询问装备、鞋子和宠物。全部选好后，我用一个switch()语句，根据用户的选择给出各自的答案。

问题是响应始终是我对 if() 条件的响应，这意味着如果不满足条件，它仍会记录相同的响应。

这是代码学院的练习；该网站说我已经满足了该程序的要求，但是当然，由于结果不正确，我想我会寻求帮助。感谢所有提前提供帮助的人。 :)

var user = prompt("Your path diverges to three roads, which one will you take?", "Forest, Mountain or Sea?").toUpperCase();
var gear = ["Oxygen tank", "Fire Starter", "Camp"]
var askGear = prompt("Choose your gear:", gear[0] + ", " + gear[1] + " or " + gear[2]).toUpperCase();
var shoes = ["Swimfin", "Studded", "BearPaw"]
var askShoes = prompt("Choose your shoes:", shoes[0] + ", " + shoes[1] + " or " + shoes[2]).toUpperCase();
var pet = ["Monkey", "Wolf", "Whale"]
var askPet = prompt("Choose your pet:", pet[0] + ", " + pet[1] + " or " + pet[2]).toUpperCase();
var choiceBank = [askGear, askShoes, askPet]
var choices = confirm("You chose to take " + askShoes + " shoes, " + askGear + " and a " + askPet + " to your adventure in the " + user + ". Are you ready to go?")
var choiceConfirm = confirm("This is your final chance, you sure?")

switch(user) {
    case "FOREST": {
        if (choiceBank[0] = 'CAMP' || 'FIRE STARTER', choiceBank[1] = 'BEARPAW', choiceBank[2] = 'WOLF' || 'MONKEY') {
            console.log("Congratulations! With those right supplies you chose, you survived to live another day!")
        } else {
            console.log("Really? You though you could survive with those supplies?")
        }
    }
        break;
    case "MOUNTAIN": {
        if (choiceBank[0] = 'CAMP' || 'FIRE STARTER', choiceBank[1] = 'STUDDED', choiceBank[2] = 'WOLF') {
            console.log("Wow! You're a survival expert!")
        } else {
            console.log("Really? You though you could survive with those supplies?")
        }   
    } 
        break;
    case "SEA": {
        if (choiceBank[0] = 'OXYGEN TANK', choiceBank[1] = 'SWIMFIN', choiceBank[2] = 'WHALE') {
            console.log("Congratulations on choosing well, you survived to live another day!")
        } else {
            console.log("Really? You though you could survive with those supplies?")
        } 
    }
        break;
    default: {
        console.log("Sorry, one of the responses was invalid, please try again.")
        }
}

Answer 1

发生了什么变化：

var 块，现在压缩为 , 分隔
statements被;
case块不需要多余的{}
if改了一些更有意义。

原代码

if (choiceBank[0] = 'CAMP' || 'FIRE STARTER',
    choiceBank[1] = 'BEARPAW', 
    choiceBank[2] = 'WOLF' || 'MONKEY') {
//                ^        ^ ^
//       assignment        or and comma

改为

if ((choiceBank[0] === 'CAMP' || choiceBank[0] === 'FIRE STARTER') &&
    choiceBank[1] === 'BEARPAW' &&
    (choiceBank[2] === 'WOLF' || choiceBank[2] === 'MONKEY')) {

choiceBank[0] = 'CAMP'是一个赋值，但是我们需要和choiceBank[0] === 'CAMP'比较，和'FIRE STARTER'一样。这应该是 'CAMP' 选择的替代方法。这是通过 logical or || 实现的。 , 被和 && 取代。 or的优先级比and小，需要加括号。

小改动：添加输出而不是 console.log

var user = prompt("Your path diverges to three roads, which one will you take?", "Forest, Mountain or Sea?").toUpperCase(),
    gear = ["Oxygen tank", "Fire Starter", "Camp"],
    askGear = prompt("Choose your gear:", gear[0] + ", " + gear[1] + " or " + gear[2]).toUpperCase(),
    shoes = ["Swimfin", "Studded", "BearPaw"],
    askShoes = prompt("Choose your shoes:", shoes[0] + ", " + shoes[1] + " or " + shoes[2]).toUpperCase(),
    pet = ["Monkey", "Wolf", "Whale"],
    askPet = prompt("Choose your pet:", pet[0] + ", " + pet[1] + " or " + pet[2]).toUpperCase(),
    choiceBank = [askGear, askShoes, askPet],
    choices = confirm("You chose to take " + askShoes + " shoes, " + askGear + " and a " + askPet + " to your adventure in the " + user + ". Are you ready to go?"),
    choiceConfirm = confirm("This is your final chance, you sure?");

switch (user) {
    case "FOREST":
        if ((choiceBank[0] === 'CAMP' || choiceBank[0] === 'FIRE STARTER') && choiceBank[1] === 'BEARPAW' && (choiceBank[2] === 'WOLF' || choiceBank[2] === 'MONKEY')) {
            out("Congratulations! With those right supplies you chose, you survived to live another day!");
        } else {
            out("Really? You though you could survive with those supplies?");
        }
        break;
    case "MOUNTAIN":
        if ((choiceBank[0] === 'CAMP' || choiceBank[0] === 'FIRE STARTER') && choiceBank[1] === 'STUDDED' && choiceBank[2] === 'WOLF') {
            out("Wow! You're a survival expert!");
        } else {
            out("Really? You though you could survive with those supplies?");
        }
        break;
    case "SEA":
        if (choiceBank[0] === 'OXYGEN TANK' && choiceBank[1] === 'SWIMFIN' && choiceBank[2] === 'WHALE') {
            out("Congratulations on choosing well, you survived to live another day!");
        } else {
            out("Really? You though you could survive with those supplies?");
        }
        break;
    default:
        out("Sorry, one of the responses was invalid, please try again.");
}

function out(s) {
    var node = document.createElement('div');
    node.innerHTML = s + '<br>';
    document.getElementById('out').appendChild(node);
}

<div id="out"></div>

Codecademy JavaScript 中的控制流编程

Control flow programming in JavaScript on Codecademy

javascript

arrays

switch-statement