[英]Input Value showing as undefined
I'm fairly new to javascript and trying to make a simple To Do list work.我是 javascript 的新手,正在尝试制作一个简单的待办事项列表。 I have the basic functionality down, but I'm trying to understand why the input value in my code is returning undefined?
我有基本功能,但我想了解为什么我的代码中的输入值返回未定义?
The remove button adds just fine, so I know the function is working.删除按钮添加得很好,所以我知道 function 正在工作。
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />
<meta name="viewport" content="width=device-width, initial-scale=1.0" />
<link rel="stylesheet" href="css/main.css" />
<title>To Do List</title>
</head>
<body>
<div class="content__container">
<div class="list__container">
<div class="header__container">
<h1 class="header__title">TO DO LIST</h1>
<input id="header__input" type="text" />
<button class="header__button">Add</button>
</div>
<div class="list__content"></div>
</div>
</div>
<script src="script.js"></script>
</body>
</html>
const btn = document.querySelector(".header__button");
const listContent = document.querySelector(".list__content");
let input = document.getElementById("header__input").value;
function addItem() {
const toDoItem = document.createElement("li");
const text = document.createTextNode(input);
const remove = document.createElement("button");
remove.textContent = "remove";
remove.classList.add("list__remove");
toDoItem.classList.add("list__items");
toDoItem.appendChild(text);
toDoItem.appendChild(remove);
listContent.appendChild(toDoItem);
}
btn.addEventListener("click", addItem);
Your script is getting the input value only when it start and not when the function is called.您的脚本仅在启动时获取输入值,而不是在调用 function 时获取输入值。
const btn = document.querySelector(".header__button");
function addItem() {
const listContent = document.querySelector(".list__content");
let input = document.getElementById("header__input").value;
const toDoItem = document.createElement("li");
const text = document.createTextNode(input);
const remove = document.createElement("button");
remove.textContent = "remove";
remove.classList.add("list__remove");
toDoItem.classList.add("list__items");
toDoItem.appendChild(text);
toDoItem.appendChild(remove);
listContent.appendChild(toDoItem);
}
btn.addEventListener("click", addItem);
Moving listContent and the input variable into the function will ensure that you get the values every time the function is executed.将listContent和输入变量移动到 function 将确保每次执行 function 时都能获得值。
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