javascript - 完成 - pureJS 写入数据的问题，有什么想法吗？

Question

我试图从“create_name()”获取数据并将结果写入

<p id="name"> </p> 

更新变量名称以显示新版本。

但是我有点诚实，它返回“未定义”作为名称。

代码显然到达了这一部分，然后失败了:

Writedata(create_name); // now write our username
menu_function();
}


function Writedata(nameUser){
    document.getElementById("name").innerHTML='hello ' + nameUser + ' below are your options'; // write the username.
}

您可以在此处查看我尝试使用的整个部分的代码。

我希望我解释得足够清楚。

有任何问题吗？请随时询问，感谢所有帮助!

init(); // lets start the inital func

function init(){ // Do some asking shit
    var name = prompt('hello, what is your name?'); // ask for the name
    document.write('<p id="name">hello ' + name + ' </p>');
    document.write('<p id="user" >1 - create a username</p>');
    document.write('<p id ="play" >2 - Play Quiz<p>');
    document.write('<p id="reload">3 - quit and reload<p>');
    Writedata(name); // tell our witer to write the name
}

function menu_function() {
    var choice = prompt("hello " + name + " please select an option from the list to your left");

    switch (choice) {
        case "1": opt1_function(); break;
        case "2": opt2_function(); break;
        case "3": reload_method(); break;
        default: menu_function(); break;
    }
}

menu_function();

function opt1_function() {
    alert(name + " you have selected option 1");
    create_name();
}

function create_name() {
    var forename = prompt("what is your forename?");
    var surname = prompt("what is your surname?");
    var username = alert("hello " + forename + " " + surname);
    var string1 = forename.substring(0 , 1);
    var create_name = alert(string1 + surname);
    Writedata(create_name); // now write our username
    menu_function();
}

function Writedata(nameUser){
    document.getElementById("name").innerHTML='hello ' + nameUser + ' below are your options'; // write the username.
}

Answer 1

停止将alert()函数返回值赋给变量，alert()没有返回值look at this alert definition

更改此行

var create_name = alert(string1 + surname);

至

alert(string1 + surname);
var create_name = string1 + surname;