我不能在這里做一個片段，因為不允許使用 localStorage。將此塊復制到一個空白文件中并將其另存為 html 文件，然后在瀏覽器中打開它。
這就是我認為您描述需求的方式，也是基于我評論中的數據格式。它不漂亮，需要大量修飾，但它可以運行。
<!DOCTYPE html>
<META HTTP-EQUIV="Content-Type" CONTENT="text/html; charset=UTF-8">
<html>
<head>
<title>Task listing</title>
<script type="text/javascript">
let taskList = [];
function checkTasks() {
let tasksList = getTasksList();
if (tasksList.length == 0) {
let newTask = prompt("Please enter a task description");
if (newTask) {
let thisIndex = getNewIndex();
let a = {"id": thisIndex, "task": newTask, "comments": []}
taskList.push(a);
saveTasksList(taskList);
}
}
displayTasks();
}
function displayTasks() {
let container = document.getElementById("tasks");
container.innerHTML = "";
let taskList = getTasksList();
taskList.forEach(function(task){
let d = document.createElement("div");
d.id = "task_" + task.id;
d.className = "commentdiv";
d.innerHTML = "<h3>" + task.task + "</h3>";
let l = document.createElement("ul");
l.id = "comments_" + task.id;
let comments = task.comments;
if (comments.length > 0) {
let commentindex = 0;
comments.forEach(function(comment) {
let c = document.createElement("li");
c.innerHTML = comment;
let cb = document.createElement("button");
cb.id = "deletecomment_" + task.id + "_" + commentindex;
cb.innerHTML = "Delete comment";
cb.onclick = function() {deleteComment(task.id, commentindex);};
c.appendChild(cb);
l.appendChild(c);
})
}
let b = document.createElement("button");
b.id = "addcomment_" + task.id;
b.onclick = function() {addComment(task.id);};
b.innerHTML = "Add comment";
d.appendChild(b);
d.appendChild(l);
container.appendChild(d);
})
}
function addComment(taskid) {
let newcomment = prompt("Enter comment");
if (newcomment) {
let tasklist = getTasksList();
let filtered = tasklist.filter(task => task.id == taskid);
if (filtered[0]) {
let thisTask = filtered[0];
thisTask.comments.push(newcomment);
let thisIndex = taskList.findIndex((task) => task.id == taskid);
taskList[thisIndex] = thisTask;
}
saveTasksList(taskList);
displayTasks();
}
}
function addNewTask() {
let newTask = prompt("Enter task description");
let taskList = getTasksList();
let lastindex = localStorage.getItem("tasksindex");
let index = getNewIndex();
let a = {"id": index, "task": newTask, "comments": []}
taskList.push(a);
saveTasksList(taskList);
displayTasks();
}
function deleteComment(taskid, commentindex) {
let tasklist = getTasksList();
let filtered = tasklist.filter(task => task.id == taskid);
// as long as there is at least one task with the taskid value, find and delete the comment
// based on the index position of the comment in the comments array
if (filtered[0]) {
let thisTask = filtered[0];
thisTask.comments.splice(commentindex, 1);
let thisIndex = taskList.findIndex((task) => task.id == taskid);
taskList[thisIndex] = thisTask;
}
saveTasksList(taskList);
displayTasks();
}
function getTasksList() {
let tasks = localStorage.getItem("tasks");
taskList = JSON.parse(tasks);
if (!taskList) {
taskList = [];
}
return taskList;
}
function saveTasksList(taskList) {
localStorage.setItem("tasks", JSON.stringify(taskList));
}
function getNewIndex() {
let lastindex = localStorage.getItem("tasksindex");
let idx = 0;
if (!lastindex) {
idx = 1;
} else {
idx = Number(lastindex) + 1;
}
localStorage.setItem("tasksindex", idx);
return idx;
}
function removeAll() {
localStorage.removeItem("tasks");
localStorage.removeItem("tasksindex");
displayTasks();
}
window.onload = checkTasks;
</script>
<style type="text/css">
.commentdiv {
border:1px solid black;
width:1000px;
padding:5px;
border-radius:5px;
}
button {
margin-left:10px;
}
h3 {
width:100%;
border-bottom: 1px dotted black;
}
ul {
list-style-type:decimal;
}
</style>
</head>
<body>
<h2>My task list <button id="addNewTaskButton" onclick="addNewTask();">Add new task</button></h2>
<hr>
<div id="tasks">
</div>
<button id="removeAll" onclick="removeAll();">Remove all tasks</button>
</body>
</html>
