javascript实现单例模式

var SingleTon = (function(){
  var initinstance;
  function myConstructor(){
    return{
      publicMethod : function(){
        alert(this.value);
      },
      value : ‘haha‘
    }
  }
  return{
    getInstance : function(){
      if(!initinstance){
        initinstance =  myConstructor();
      }
      return initinstance;
    }
  }
})()
SingleTon.getInstance().publicMethod();