lovecoding
/
VIP24


			
							12345678910111213141516171819202122232425262728293031323334353637383940414243444546474849505152535455565758596061626364656667686970717273747576777879808182838485
							<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8">
  <meta http-equiv="X-UA-Compatible" content="IE=edge">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #div1{
      width: 200px;
      height: 200px;
      background: red;
    }
    #div2{
      width: 200px;
      height: 200px;
      background: blue;
    }
    .xxx{
      background: gray;
    }
  </style>
</head>
<body>
  <div id="div1">123</div>
  <div id="div2">123</div>

  <div class="xxx">222</div>
  <div>333</div>
  <div>444</div>
  <div class="xxx">555</div>
  <ul >
    <li class="xxx">1</li>
    <li>2</li>
    <li class="xxx">3</li>
    <li>4</li>
    <li class="xxx">5</li>
    <li>6</li>
  </ul>
  <ul id="ul2">
    <li >1</li>
    <li class="xxx">2</li>
    <li >3</li>
    <li class="xxx">4</li>
    <li >5</li>
    <li class="xxx">6</li>
  </ul>

  <button id="btn">点击</button>
  <script>
    var btn = document.getElementById('btn')

    var div1 = document.getElementById('div1')

    var xxx = document.getElementsByClassName('xxx')//返回的是一个数组[]
    var ul1 = document.getElementsByTagName('ul')//返回的是一个数组[]

    var ul2 = document.getElementById('ul2')
    var li1 = ul2.getElementsByClassName('xxx')
    console.log(ul1)
    console.log(xxx)
    console.log(div1) 
    btn.onclick = function(){
      div1.style.background = 'green'
      console.log(123)
    }
    for(var i=0;i<xxx.length;i++) {
      xxx[i].style.background = 'green'
    }
    for(var j=0;j<ul1.length;j++){
      var lixxx = ul1[j].getElementsByClassName('xxx')//返回的是一个数组[]
      console.log(lixxx)
      for(var x=0;x<lixxx.length;x++){
        lixxx[x].style.background = 'orange'
      }
    }
    for(var n=0;n<li1.length;n++){
      li1[n].style.background = 'purple'
    }


  </script>
</body>
</html>