Channels in Go are the primary mechanism for communication between goroutines. They act as pipes that allow one goroutine to send data to another goroutine safely. This enables concurrent programs to coordinate and share information without the need for explicit locks or shared memory.
There are two main types of channels in Go: unbuffered and buffered channels. Unbuffered channels are created with make chan int and provide synchronous communication where the sender blocks until a receiver is ready. Buffered channels are created with make chan int comma capacity and can hold multiple values, allowing asynchronous communication up to their buffer size.
Channel operations use the arrow operator. To send data, we use ch arrow value, which sends a value into the channel. To receive data, we use value colon equals arrow ch, which receives a value from the channel. The send operation blocks until another goroutine is ready to receive, and the receive operation blocks until data is available.
The select statement is a powerful feature that lets a goroutine wait on multiple channel operations simultaneously. It has a similar syntax to switch but works with channels. Each case specifies a channel operation, and select will execute the first case that becomes ready. If no case is ready and there's a default case, it runs immediately, making the select non-blocking.