了解：
node安装，node函数异步，node回调机制；
API：
An API (Application Programming Interface) is a set of features and rules that exist inside a software program (the application) enabling interaction with it through software - as opposed to a human user interface. The API can be seen as a simple contract (the interface) between the application offering it and other items, such as third party software or hardware.
node.js Design Patterns:
The reactor pattern:
The callback pattern：
Synchronous continuation-passing style and Asynchronous continuation-passing style
Node.js callback conventions：
Callbacks come last and Error comes first
Errors:
The module system and its patterns:
Exports:
Modifying other modules or the global scope;
The EventEmitter:
了解： node安装，node函数异步，node回调机制； API： An API (Application Programming Interface) is a set of features and rules that exist inside a software program (the application) enabling interaction with it through software - as opposed to a human user interface. The API can be seen as a simple contract (the interface) between the application offering it and other items, such as third party software or hardware. node.js Design Patterns: The reactor pattern: The callback pattern： Synchronous continuation-passing style and Asynchronous continuation-passing style Node.js callback conventions： Callbacks come last and Error comes first Errors: The module system and its patterns: Exports: Modifying other modules or the global scope; The EventEmitter: