设计模式之单例模式

  var singleton = (function(){
    var instance;
    function init(){
      function privateMethod(){
        console.log(‘privateMethod‘);
      }
      var privateVar = ‘privateVar‘;
      return {
        publicMethod : function() {
          console.log(‘publicMethod‘);
        },
        publicVar : ‘publicVar‘
      }
    }

    return {
        getInstance : function () {
          if(!instance){
            instance = init();
          }
          return instance;
        }
    }
  })();

  var n1 = singleton.getInstance();
  var n2 = singleton.getInstance();
  console.log(n1 === n2)