net.createConnection(port[, host][, connectListener])

• port <number> 套接字应该连接的端口号. 会  传给socket.connect(port[, host][, connectListener]).
• host <string> 套接字应该连接的主机名. 会 传给socket.connect(port[, host][, connectListener]).   默认: 'localhost'
• connectListener <Function>  net.createConnection() 的常见参数, 在初始化套接字时  对'connect' 事件的"一次性"监听器， 会  传给socket.connect(path[, connectListener]).
• 返回值: <net.Socket> 用于开启连接的新创建的套接字.

初始化一个TCP连接

这个函数用默认配置创建一个新的net.Socket，然后socket.connect(port[, host][, connectListener])初始化一个连接，并返回开启连接的那个 net.Socket。

• port <number> Port the socket should connect to. Will be passed to socket.connect(port[, host][, connectListener]).
• host <string> Host the socket should connect to. Will be passed to socket.connect(port[, host][, connectListener]). Default: 'localhost'.
• connectListener <Function> Common parameter of the net.createConnection() functions, an "once" listener for the 'connect' event on the initiating socket. Will be passed to socket.connect(path[, connectListener]).
• Returns: <net.Socket> The newly created socket used to start the connection.

Initiates a TCP connection.

This function creates a new net.Socket with all options set to default, immediately initiates connection with socket.connect(port[, host][, connectListener]), then returns the net.Socket that starts the connection.