12.6_weakmap_has().html

<!DOCTYPE html>
<html>
<head>
	<meta charset="utf-8">
	<title>Example WeakMap has()</title>
</head>
<body>
	<script type="text/javascript">
		var wm = new WeakMap();

		var object1 = {};
		var object2 = {};
		var object3 = {};
		var object5 = {};

		wm.set(object1, "HTML");
		wm.set(object2, "CSS");
		wm.set(object3, "JavaScript");

		document.writeln("To check if 'HTML' exist or not : " + wm.has(object1) + "<br>");

		document.writeln("To check if there is any value at key object5 : " + wm.has(object5) + "<br>");
	</script>
</body>
</html>