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

<head>
	<meta charset="utf-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
</head>
<style>
    *{
        margin: 0;
        padding: 0
    }
    #app{
        width: 400px;
        height: 400px;
        border:1px solid black;
    }

</style>
<body>

	<div id="app">
		
	</div>
</body>
<script>
    var app = document.getElementById('app')
    document.onmousemove = (e) => {
        app.innerHTML  = `e.clientX: ${e.clientX}<br>e.clientY: ${e.clientY}`
    }
</script>
</html>