观察 Chrome DevTools 中的节点数量，我想知道单击 Button1 后的 dom 树和单击 Button2 后的 dom 树有什么区别。
索引.html
<html>
<head>
<script src="./js/main.js" type="text/javascript" charset="utf-8"></script>
<link rel="stylesheet" href="style/default.css">
</head>
<body>
<div id="buttons">
<div class="button" id="button1">Execute1</div>
<div class="button" id="button2">Execute2</div>
</div>
<div id="main"></div>
<div id="main2"></div>
</body>
</html>
main.js
document.addEventListener( "DOMContentLoaded", function() {
var button1 = document.getElementById('button1');
button1.addEventListener('click', function() {
document.getElementById('main').innerHTML += '<div>hello</div>';
});
var button2 = document.getElementById('button2');
button2.addEventListener('click', function() {
var div = document.createElement('div');
div.appendChild(document.createTextNode('hello2'));
document.getElementById('main2').appendChild(div);
});
} );
默认.css
#buttons {
display:-webkit-flex;
align-items: center;
}
.button {
height: 30px;
width: 100px;
margin: 5px;
background-color: #0080C0;
color: #FFFFFF;
display:-webkit-flex;
align-items: center;
justify-content: center;
cursor: pointer;
}
When I click the Button1, the number of nodes is incremented by 4.
But when I click the button2, the number of nodes is incremented by 2.
Be incrementing by 2 makes sense for me as they could be a 'div' element and a text node 'hello2'.
But clicking the Button1, what other nodes be appended?
Using appendChild将新的 DOM 元素添加到父节点的末尾。
Using innerHTML +=获取父节点的现有 DOM 内容，将其序列化为字符串中的 HTML，在字符串末尾添加更多 HTML，擦除父节点中的现有元素，从该字符串生成 DOM 元素，然后附加新节点到父节点。