Buffered Channels

for value := range ch{
    ...
}

• Iterator over values received from a channel.
• Loop automatically breaks, when a channel is closed.
• Range does not return the second boolean value.

Unbuffered Channels

• Synchronous ch := make(chan T)

Buffered Channels

• Asynchronous
• Channels are given capacity
• in-memory FIFO queue

ch := make(chan T, capacity)

Exercises

Range

https://go.dev/play/p/o535FRB4mV8

package main

import "fmt"

func main() {
    ch := make(chan int)
    go func() {
        for i := 0; i < 6; i++ {
            // send iterator over channel
            ch <- i
        }
        close(ch)
    }()

    // range over channel to recv values
    for value := range ch {
        fmt.Println(value)
    }
}

0
1
2
3
4
5

Buffered Channels

https://go.dev/play/p/rg1tmIAi8HX

package main

import (
    "fmt"
)

func main() {
    ch := make(chan int, 6)

    go func() {
        defer close(ch)

        // send all iterator values on channel without blocking
        for i := 0; i < 6; i++ {
            fmt.Printf("Sending: %d\n", i)
            ch <- i
        }
    }()

    for v := range ch {
        fmt.Printf("Received: %v\n", v)
    }
}

Sending: 0
Sending: 1
Sending: 2
Sending: 3
Sending: 4
Received: 0
Received: 1
Received: 2
Received: 3
Received: 4
Sending: 5
Received: 5