开关块javascript中的if语句答案

【问题标题】：If statement in a switch block javascript开关块javascript中的if语句
【发布时间】：2015-11-18 19:31:19
【问题描述】：

是否可以在 Javascript 的 switch 块中使用来自 switch 块的响应的 if/else 语句？以下是我的尝试。这是一个 CodeAcademy 项目，您必须在其中使用 switch 块和条件语句编写自己的冒险代码。

var user = prompt("You awake; dazed, blurred and lost. What do you do?").toLowerCase()
var day = 0;

switch (user) {
    case "look at the time":
        console.log("Good start, how long was I out for?");
        if (
        case "look at the time" && day === 0) {
            console.log("it's only been a few hours, but time is still ticking");
            day++
        } else if (day > 0) {
            console.log("it's been " + day + "s! Will I make it out of here");
            day++
        }
        break;
    case "figure out where I am":
        console.log("Yeah, how did I end up here in the first place?");
        if (
        case "figure out where I am" && day === 0) {
            console.log("This is a good checkpoint");
            day++
        }
        break;
    case 'run':
        console.log("Dry your eyes, find a direction, and hope for the best");
        break;
    case 'give up':
        console.log('Thanks for trying, have fun, where ever you are...');
        break;
    default:
        console.log("you fall back unconscious, hoping to wake again");
        day++;
        if (
        default) {
            return user;
        }
        if (
        case 'run' ||
        case 'give up') {
            console.log("It would have ended up coming down to this option anyway");
        }
}

【问题讨论】：

您无需再次检查（也不能）case，只需检查day。
不，不能将 if 语句放在 switch 块内。您只能将cases 放在那里。而且您也不能将cases 放在if-conditions 中。这只是一个语法错误。

标签： javascript if-statement switch-statement conditional

【解决方案1】：

如果您在if 语句中进行更改以停止使用单词case，它将起作用，例如，与case 语句中的user 变量进行比较时应该如下所示：

if (user === "look at the time" && day === 0) {
    console.log("it's only been a few hours, but time is still ticking");
    day++
} else if (day > 0) {
    console.log("it's been " + day + "s! Will I make it out of here");
    day++
}

在这种情况下，比较 user === "look at the time" 是多余的，因为该逻辑已经在 switch 语句本身中进行了评估。我只是将它包含在内，以便您可以查看如何与 user 变量进行比较，但在这种情况下可以完全排除它并具有相同的效果。

【讨论】：