SOURCE

console 命令行工具 X clear

                    
>
console
<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<title>pick</title>
</head>
<body>
	<script type="text/javascript">
		function invert(obj) {
			for (let k in obj) {
				let name = obj[k];
				obj[name] = k;
				delete obj[k];
			}
			return obj;
		}
		const obj = {firstname: "lv", lastname: "meijin"};
		console.log(invert(obj));
	</script>
</body>
</html>