js_checker.html

<!DOCTYPE html>
<html>
<head>
	<title>js checker</title>
</head>
<body>
	<textarea id="jscode"></textarea>
	<button id="checking">Check Javascript code</button>
	<script type="text/javascript">
		

		$g = function(componet){
			return document.querySelector(componet);
		};

		document.getElementById('checking').onclick = function(){

			try{

				var code = $g('#jscode').value;

				return (function(code){
					eval(code);
				})(code);


			}catch(e){
				console.log(e);
			}

		};
		
	</script>
</body>
</html>