js单例使用

 单例模式
 1 var mySingleton = (function(){
    var instance;
    function init(){
        function privateMehod(){
            console.log(111);
        };
        var privateVar = '11111';
        var privateRandomNumber = Math.random();
        return {
            publicMethod:function(){

            },
            publicVar:2222,
            getRandomNumber:function(){
                return privateRandomNumber
            }
        }
    };
    return {
        getInstance: function(){
            if(! instance){
                instance = init();
            };
            return instance
        }
    }
})();
调用方式：

1. mySingleton // getInstance:function(){}

2. mySingleton.getInstance() // publicMethod: function, publicVar: 2222, getRandomNumber: function

3. mySingleton.getInstance().publicVar //222