我如何连接用户的输入和功能

你可以声明全局变量，并使用它来连接你的点击事件和开关函数。别忘了在switch之后把它设回null。可以这样做:

// This is a button click function. When user clicks the Enter button with the left mouse, all the text from the input appends to the "story board".
var in;
$("#btn").click(function(){
        // set `in` variable from user input
        var btnClick = in = $("input[name=myInput]").val();
        $("#storyBoard").append(btnClick+"<br>");
        $("input[name=myInput]").val("");
        var element = document.getElementById("storyBoard");
element.scrollTop = element.scrollHeight;
        });

// It is an additional function for button click function, that allows user to press enter button on a keyboard to call the click button function.
 $("#userInput").keyup(function(event){
    if(event.keyCode == 13){
        $("#btn").click();
    }
});
/* Here i stucked. I writed a sketch switch(), but how do i connect between this and the user input? */
var mission1 = function(){
    showText("Welcome to the virtual pseudo-reality.<br> Are you ready to start your journey?");
        var readyToStart = function(){
            //switch `in` variable
            switch(in){
            case "yes": console.log("yes");
            break;
            case "no": console.log("no");
            break;
            default: console.log("yes or no?");
                readyToStart();
            }
            //set `in` to original
            in = "";
        }

如果我是你，我会这样做:

<form>
  <input type="text" id ="userInput" placeholder="Type the command here" name="myInput"/>
  <button type="submit" id = "btn"> Enter </button>
</form>

，然后在JS中:

$("#btn").submit(function(e){
   e.prevetDefault();
   //your code...
   var choice = $("#userInput").val();
   switch(choice){...}
  //rest of your code...

现在回车应该和鼠标点击

我首先建议您使用HTML表单标签，使用onsubmit="submitted()"和submitted函数来使用event.preventDefault()，而不是所有这些BS提交

第二，你应该在"conversation"循环中应用一些逻辑，使用promise。

意味着你的代码看起来像:

let currentState = {
    options: null,
    promise: null
};
function newMessage(text, options = null) {
    currentState.options = options;
    currentState.promise = new Promise();
    return currentState.promise;
}
newMessage("Ready to start?", ["yes", "no"]).then((message) => {
    switch(message) {
        case "yes":
            newMessage("Great! your name please?").then((name) => {
                alert("your name is " + name);
            });
            break;
        case "no":
            newMessage("So what are you doing here!?!?").then((password) => {
                if(password == "BLAH") {
                    alert("you have found an easter egg");
                }
            });
            break;
    }
});
function submitted(event) {
    event.preventDefault();
    let value = document.getElementById('my-input').value;
    if(currentState.options !== null) {
        if(!currentState.options.indexOf(value)) {
            alert("Options are: "+JSON.stringify(currentState.options));
            return;
        }
    }
    currentState.promise.resolve(value);
}

我通常不为别人写代码，所以把这作为一个方向