console 命令行工具 X clear
console
<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1, minimum-scale=1, maximum-scale=1, user-scalable=no">
    <meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1" />
    <title>demo</title>
    <script src="https://code.jquery.com/jquery-3.2.1.min.js"  integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>
    <style>
        * {
            margin: 0;
            padding: 0;
        }

        html {
        }

        body,
        html {
            width: 100%;
            height: 100%;
        }
    </style>
</head>

<body>
     <input id="txt" type="text">
</body>
<script>
    $(function() {
        $('#txt').on('compositionstart',function(){
          console.log(1)
        })
        $('#txt').on('compositionend',function(){
          console.log(2)
        })
    })
</script>

</html>