What are channels used for?

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chan is a channel in Golang. In simple word you can think it as a box in which you put a item at one end and then pick it from other end.

Unbuffered Channels

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Buffered Channel

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This is the small code I have written for you to understand channels. Now change order of go routines and see the outputs. Each time output may differ.

    package main

    import (
        "fmt"
        "time"
    )

    func main() {
        messages := make(chan int)
        go func() {
            time.Sleep(time.Second * 3)
            messages <- 1
        }()
        go func() {
            time.Sleep(time.Second * 2)
            messages <- 2
        }() 
        go func() {
            time.Sleep(time.Second * 1)
            messages <- 3
        }()
        go func() {
            for i := range messages {
                fmt.Println(i)
            }
        }()
        go func() {
            time.Sleep(time.Second * 1)
            messages <- 4
        }()
        go func() {
            time.Sleep(time.Second * 1)
            messages <- 5
        }()
        time.Sleep(time.Second * 5)
    }

For best understanding visit this blog where go routines and channels are described in GUI.

Visit http://divan.github.io/posts/go_concurrency_visualize/

More Related Contents:

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  2. How to broadcast message using channel
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  4. If I am using channels properly should I need to use mutexes?
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  6. Goroutine does not execute if time.Sleep included
  7. How to collect values from N goroutines executed in a specific order?
  8. Closing channel of unknown length
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