Javascript:如何简化具有多个 OR 条件的 if 语句？

Question

很抱歉，如果我在写这篇文章时犯了错误。我是新来的，不知道这是如何工作的，希望我能尽快学会。我也是 JavaScript 新手。

所以问题是:我的 code.elements.js 文件中有这个，但我无法让它工作。

放置这个有用吗？

if (codePrompt == (codeSwitch || codeSwitchBG || codeBlur || codeShowInfo)){};

或者我必须通过正常方式做到这一点？，比如

if (codePrompt == codeSwitch || codePrompt == codeSwitchBG || codePrompt == codeBlur || codePrompt == codeShowInfo){};


var codeSwitch = 'switch()';
var codeSwitchBG = 'switch(background)';
var codeBlur = 'blur()';
var codeShowInfo = 'showInfo()';

$(".code").on("click", function () {
var codePrompt = prompt("Set the code in the command line.");
if (codePrompt == (codeSwitch || codeSwitchBG || codeBlur || codeShowInfo)) {
    if (codePrompt == codeSwitch) {
        alert("Switching background...");
        console.log("Used '" + codeSwitch + "' command.");
    } else if(codePrompt == codeBlur) {
        alert("Blurring elements...");
        console.log("Used '" + codeBlur + "' command.");
    } else if(codePrompt == codeSwitchBG) {
        alert("Switching background...");
        console.log("Used '"+ codeSwitchBG + "' command.");
    }else if(codePrompt == codeShowInfo) {
        alert("Showing info...");
        console.log("Used '"+ codeShowInfo + "' command.");
    }
} else {
    alert("Wrong command, try again.");
    console.log("Wrong command, try again.");
};
});

Answer 1

“正常”方式按照您可能期望的方式工作。

但是，无论如何，if 语句是多余的。您可以跳过它:

if (codePrompt === codeSwitch) {
    alert("Switching background...");
    console.log("Used '" + codeSwitch + "' command.");
} else if (codePrompt === codeBlur) {
    alert("Blurring elements...");
    console.log("Used '" + codeBlur + "' command.");
} else if (codePrompt === codeSwitchBG) {
    alert("Switching background...");
    console.log("Used '" + codeSwitchBG + "' command.");
} else if (codePrompt === codeShowInfo) {
    alert("Showing info...");
    console.log("Used '" + codeShowInfo + "' command.");
} else {
    alert("Wrong command, try again.");
    console.log("Wrong command, try again.");
}

这是一个很好的switch 用例，我会这样重构它:

var alertMessage = "",
    consoleMessage = "Used '" + codePrompt + "' command.";
switch (codePrompt) {
    case codeSwitch:
        alertMessage = "Switching background...";
        break;
    case codeBlur:
        alertMessage = "Blurring elements...";
        break;
    case codeSwitchBG:
        alertMessage = "Switching background...";
        break;
    case codeShowInfo:
        alertMessage = "Showing info...";
        break;
    default:
        alertMessage = consoleMessage = "Wrong command, try again.";
        break;
}
alert(alertMessage);
console.log(consoleMessage);