javascript 8 singleton impl

 <script>
        var cct = 5;
        //1st way
        var singleton1 = {
            count: 0,
            add: function () {
                this.count++;
            }
        };

        for (var i = 0; i < cct; i++) {
            singleton1.add();
            console.log(singleton1.count);
        }
        console.log('=================');
        //2nd way
        var singleton2 = function () {
            return {
                count: 0,
                add: function () {
                    this.count++;
                }
            };
        }

        var s2 = singleton2();
        for (var i = 0; i < cct; i++) {
            s2.add();
            console.log(s2.count);
        }
        console.log('=================');

        //3rd way (lazy load)
        var singleton3 = (function () {
            function init() {
                return {
                    count: 0,
                    add: function () {
                        this.count++;
                    }
                };
            }

            var instance;
            return {
                getInstance: function () {
                    if (!instance) {
                        instance = init();
                    }
                    return instance;
                }
            };
        })();
        for (var i = 0; i < cct; i++) {
            singleton3.getInstance().add();
            console.log(singleton3.getInstance().count);
        }
        console.log('=================');

        //the best way
        var singleton4 = (function () {
            function sst() {
                this.count = 0;
                this.add = function () {
                    this.count++;
                }
            }

            var instance;
            return {
                getInstance: function () {
                    if (!instance) {
                        instance = new sst();
                    }
                    return instance;
                }
            };
        })();
        for (var i = 0; i < cct; i++) {
            singleton4.getInstance().add();
            console.log(singleton4.getInstance().count);
        }
        console.log('=================');

        function singleton5() {
            if (typeof singleton5.instance === 'object') {
                return singleton5.instance;
            }
            this.count = 0;
            this.add = function () {
                this.count++;
            };
            singleton5.instance = this;
        }

        for (var i = 0; i < cct; i++) {
            var dd = new singleton5();
            dd.add();
            console.log(dd.count);
        }
        console.log('=================');

        function singleton6() {
            var instance = this;
            this.count = 0;
            this.add = function () {
                this.count++;
            };

            singleton6 = function () {
                return instance;
            }
        }
        for (var i = 0; i < cct; i++) {
            var dd = new singleton6();
            dd.add();
            console.log(dd.count);
        }
        console.log('=================');

        function singleton7() {
            var instance;
            singleton7 = function singleton7() {
                return instance;
            };
            instance = new singleton7();
            instance.constructor = singleton7;

            instance.count = 0;
            instance.add = function () {
                instance.count++;
            };

            return instance;
        }
        for (var i = 0; i < cct; i++) {
            var dd = singleton7();
            dd.add();
            console.log(dd.count);
        }

        console.log('=================');

        var singleton8;
        (function () {
            var instance;
            singleton8 = function singleton8() {
                if (instance) {
                    return instance;
                }
                instance = this;
                this.count = 0;
                this.add = function () {
                    this.count++;
                };
            }
        }());

        for (var i = 0; i < cct; i++) {
            var dd = new singleton8();
            dd.add();
            console.log(dd.count);
        }
        console.log('=================');

    </script>