Channels

Channels are the pipes that connect concurrent Goroutines. You can send values into channels from one goroutine and receive those values in another goroutine.

Creating a Channel

Channels are typed. You use the make built-in to create them:

ch := make(chan int) // Creates a channel of integers

Sending and Receiving

You use the <- operator to send or receive data.

package main

import "fmt"

func main() {
    ch := make(chan string)

    go func() {
        // Send to channel
        ch <- "Ping from Goroutine!"
    }()

    // Receive from channel
    msg := <-ch
    fmt.Println(msg)
}

Buffered vs Unbuffered

By default, channels are unbuffered, meaning that sends block until the receiver is ready. You can create buffered channels that accept a limited number of values without a receiver:

ch := make(chan int, 100) // Buffer size of 100

Channels are a fundamental piece of Go’s concurrency model. To understand where they fit in the broader language, refer back to the Introduction.