spectrox/singleton.html

## singleton.html
<!DOCTYPE html>
<html>
<head>
    <title>Singleton Example</title>
</head>
<body>
<script>
    // one way to create Singleton
    console.log('first way:');

    var Singleton;

    (function(){
        var instance;

        Singleton = function Singleton() {
            if (instance) {
                return instance;
            }

            instance = this;
        }

        Singleton.prototype = {
            setMessage: function(message) {
                this.msg = message;
            },
            getMessage: function() {
                return this.msg;
            }
        }
    }());

    var s1 = new Singleton();
    s1.setMessage('test1');

    var s2 = new Singleton();
    s2.setMessage('test2');

    console.log(s1.getMessage());
    console.log(s2.getMessage());

    s2.setMessage('test3');

    console.log(s2.getMessage());
    console.log(s1.getMessage());

    delete(Singleton);

    // second way
    console.log('second way:');

    function Singleton() {
        if (typeof Singleton.instance === 'object') {
            return Singleton.instance;
        }

        this.msg = 'Message';

        Singleton.instance = this;
    }

    var s1 = new Singleton();
    var s2 = new Singleton();

    console.log(s1.msg);
    console.log(s2.msg);

    s2.msg = 'New message';

    console.log(s1.msg);
    console.log(s2.msg);
</script>
</body>
</html>
	<!DOCTYPE html>
	<html>
	<head>
	<title>Singleton Example</title>
	</head>
	<body>
	<script>
	// one way to create Singleton
	console.log('first way:');

	var Singleton;

	(function(){
	var instance;

	Singleton = function Singleton() {
	if (instance) {
	return instance;
	}

	instance = this;
	}

	Singleton.prototype = {
	setMessage: function(message) {
	this.msg = message;
	},
	getMessage: function() {
	return this.msg;
	}
	}
	}());

	var s1 = new Singleton();
	s1.setMessage('test1');

	var s2 = new Singleton();
	s2.setMessage('test2');

	console.log(s1.getMessage());
	console.log(s2.getMessage());

	s2.setMessage('test3');

	console.log(s2.getMessage());
	console.log(s1.getMessage());

	delete(Singleton);

	// second way
	console.log('second way:');

	function Singleton() {
	if (typeof Singleton.instance === 'object') {
	return Singleton.instance;
	}

	this.msg = 'Message';

	Singleton.instance = this;
	}

	var s1 = new Singleton();
	var s2 = new Singleton();

	console.log(s1.msg);
	console.log(s2.msg);

	s2.msg = 'New message';

	console.log(s1.msg);
	console.log(s2.msg);
	</script>
	</body>
	</html>