<div class="box">abc</div>
<div id="id">def</div>
<script>
    var elems = document.querySelectorAll('div');
    console.log(elems);
</script>

<div>
    <span>hello world</span>
    <span>hello world</span>
</div>
<script>
    var div = document.querySelector('div');
    // 讀取 div 內(nèi)部?jī)?nèi)容
    console.log(div.innerText);
    // 修改 div 內(nèi)部?jī)?nèi)容, 界面上就會(huì)同步修改
    div.innerText = 'hello js <span>hello js</span>';
</script>

<div>
    <span>hello world</span>
    <span>hello world</span>
</div>
<script>
    var div = document.querySelector('div');
    // 讀取頁(yè)面內(nèi)容
    console.log(div.innerHTML);
    // 修改頁(yè)面內(nèi)容
    div.innerHTML = '<span>hello js</span>'
</script>

//修改屬性
<img src="rose.jpg" alt="這是一朵花" title="玫瑰花">
<script>
    var img = document.querySelector('img');
    img.onclick = function () {
        if (img.src.lastIndexOf('rose.jpg') !== -1) {
            img.src = './rose2.png';
       } else {
            img.src = './rose.jpg';
       }
   }
</script>
//獲取屬性
<img src="rose.jpg" alt="這是一朵花" title="玫瑰花">
<script>
    var img = document.querySelector('img');
    // console.dir(img);
    console.log(img.src);
    console.log(img.title);
    console.log(img.alt);
</script>

<input type="button" value="播放">
<script>
    var btn = document.querySelector('input');
    btn.onclick = function () {
        if (btn.value === '播放') {
            btn.value = '暫停';
       } else {
            btn.value = '播放';
       }
   }
</script>