Go - channel - basic

• Declare
• ch := make(chan int) // unbuffered, send will be blocked until receive was called
• ch := make(chan int, 0) // unbuffered, send will be blocked until receive was called
• ch := make(chan int, 3) // buffered, send will not be blocked until receive was called
• Channel is comparable 
• Can send msg from one channel to another by method send
• Ex.send: ch <- x
• Ex. Receive: x <- ch
• Ex. Receive and discard result: <- ch
• Close a channel by method: close
• Ex. close(ch)