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goldEli / Front-End-Training

Front End Training
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> ``` #25

Closed lurasso closed 4 years ago

lurasso commented 4 years ago 
<head>
  <meta charset="UTF-8">
  <meta name="viewport" content="width=device-width, initial-scale=1.0">
  <title>Document</title>
  <style>
    #green{
      color: green;
    }
    #red{
      color: red;
    }
  </style>
</head>
<body>
<button  id="green">点击</button>  
  <script type="text/javascript">
  var btn  = document.getElementsByTagName('button')[0];
  var count = 0;
  btn.onclick = function(){
    if(count++ %2 == 0){
    document.getElementById('green').id = 'red';
    }else{
      document.getElementById('red').id = 'green';
    }
  }
</script>
</body>

修改为ID获取DOM