Javascrit .createTextNode输出产生错误

Question

我创建了一个网站告诉你你的年龄。我使用document.createTextNode来存储输出，但是输出不能正常工作。这是输出代码

var h1 = document.createElement("p");
h1.setAttribute("id", "mainText")
var mainText = document.createTextNode("You are ", ageYears, " years, ", ageMonths, " 
months and ", ageDays, " days old.");
h1.appendChild(mainText);
document.getElementById("new-age").appendChild(h1);

当我运行我的代码时，它只输出第一部分“您是”。有没有办法输出整个消息。

Answer 1

在JavaScript中，您使用+而不是.连接字符串。

工作示例

var h1 = document.createElement("p");
h1.setAttribute("id", "mainText");
let ageYears = 20;
let ageMonths = 12
let ageDays = 24;
var mainText = document.createTextNode("You are " + ageYears + " years, " + ageMonths  + " months and " + ageDays + " days old.");
h1.appendChild(mainText);
document.getElementById("new-age").appendChild(h1);

<div id="new-age"></div>

​

Answer 2

由于document.createTextNode只接收一个参数作为数据，所以您应该像下面的代码一样更改您的document.createTextNode，以便使用您的数据生成一个字符串：(在您的代码中，因为您使用,连接字符串，所以实际上您要将多个字符串传递给document.createTextNode，它只读取第一个参数，忽略其他参数)。

var mainText = document.createTextNode("You are " + ageYears + " years, " + ageMonths + "months and " + ageDays + " days old.");

或者：

var mainText = document.createTextNode(`You are ${ ageYears} years, ${ageMonths} months and ${ageDays} days old.`);

以下是一个例子：

​

const ageYears = 30;
const ageMonths = 10;
const ageDays = 22;

function appendText() {
  let p = document.createElement("p");
  let mainText = document.createTextNode(`You are ${ ageYears} years, ${ageMonths} months and ${ageDays} days old.`);

  p.appendChild(mainText);
  document.getElementById("new-age").appendChild(p);
}

document.getElementById('appendBtn').addEventListener('click', appendText)

<div id="new-age"></div>
<button id="appendBtn">append text</button>

​