update

04-dom-events-async/12-prepend-remove-and-link-default/starter.js

@@ -4,3 +4,26 @@
 // 3. 点击 clear-active-btn 时移除所有 item 的 active 类名
 // 4. 点击帮助链接时，用 preventDefault() 阻止跳转
 // 5. 在提示文字里输出“已阻止默认跳转”
+const prependBtn = document.getElementById("prepend-btn")
+const clear = document.getElementById("clear-active-btn")
+const helpLink = document.getElementById("help-link")
+const hintText = document.getElementById("hint-text")
+const messageList = document.getElementById("message-list")
+
+prependBtn.addEventListener("click", function () {
+  const li = document.createElement("li")
+  li.classList.add("item")
+  messageList.prepend(li)
+})
+
+clear.addEventListener("click", function () {
+  const a = document.querySelectorAll("#message-list li")
+  a.forEach(item => {
+    item.classList.remove("active")
+  })
+})
+
+helpLink.addEventListener("click", function (event) {
+  event.preventDefault()
+  hintText.textContent = "已阻止默认跳转"
+})