12.5_weakset_methods.html

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<html>
<head>
	<meta charset="utf-8">
	<title>Example WeakSet add(), has() and delete()</title>
</head>
<body>
	<script type="text/javascript">
		var w = new WeakSet();

		var object1 = {};
		var object2 = {};

		w.add(object1);
		w.add(object2);

		document.writeln("Before deleting object2: <br><br>");

		document.writeln("To check if 'object1' exist in WeakSet 'w' : " + w.has(object1) + "<br>"); //explains has()
		document.writeln("To check if 'object2' exist in WeakSet 'w' : " + w.has(object2) + "<br><br>");
		// document.writeln("To check if 'object3' exist in WeakSet 'w' : " + w.has(object3) + "<br>");

		document.writeln("After deleting object2: <br><br>");

		w.delete(object2); //explains delete()
		
		document.writeln("To check if 'object1' exist in WeakSet 'w' : " + w.has(object1) + "<br>");
		document.writeln("To check if 'object2' exist in WeakSet 'w' : " + w.has(object2) + "<br>");
	</script>
</body>
</html>