todolist案例的使用
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
</head>
<body>
<input type="text" name="info" />
<button>提交</button>
<ul></ul>
</body>
</html>
<script>
let input = document.getElementsByName("info");
let button = document.getElementsByTagName('button')[0];
let ul = document.getElementsByTagName('ul')[0];
button.onclick = function(){
let li = document.createElement('li');
li.innerHTML = input.value;
ul.appendChild(li);
input.value = '';
}
</script>