Golang Channels Or Wait Groups? Let Me Explain.

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[ehSamurai]

TL;DR

Use waitgroups when you don't want goroutine to return some data.
Use channels when you do want goroutine to return some data.

[ZhaksylykAshim]

pls make a video about fan-in, fan-out patterns and usage of select keyword when working with multiple channels (also would be great if buffers, read and write chanells would be also discussed). My appreciation, maestro!

[matiasbpg]

I think you could skip the wg in the last example by using just an int that is decremented inside the for loop and making the loop sync inside the main. When the last value is received and the counter is zero, just close the channel and the execution of the main function continues

[EricT]

From now on I am calling my wait groups "weegee" :D

Amazing video! I learned to add the waiter and the close into an anonymous go routine and keep the code out of the anonymous go routine.
Thanks for this rich material

[rielj]

I think the reason why it didn't execute the last print is that the block that executes the channels' print is in a separate go routine, and the main function is also a go routine meaning that it's not included on the WaitGroup, such that once the WaitGroup is done on the main go routine it already exited the function hence the print inside the go routine is not included on the WaitGroup and is executed after the main go routine has done its task.

[athinodorossgouromalliis]

GG video man. When I was learning golang the when to use go routines with channels was a bit hard to understand and I wish your video was out back then! Cheers mate good job

[MightyMoud]

Is there a way to do without a WG when you don't know how many routines will be there?

[jamesblackman]

Great - really good simple demo - thanks

[vanshajdhar]

Best video on channels and waitgroups ❤

[kronst]

Are there any disadvantages of using this approach? For example if we need to make multiple parallel requests to fetch different type of results.

func main() {
start := time.Now()

var r1 string
var r2 int
var r3 time.Time

wg := sync.WaitGroup{}
wg.Add(3)

go func(wg *sync.WaitGroup) {
r1 = "Hello"
time.Sleep(1 * time.Second)
wg.Done()
}(&wg)

go func(wg *sync.WaitGroup) {
r2 = 42
time.Sleep(2 * time.Second)
wg.Done()
}(&wg)

go func(wg *sync.WaitGroup) {
r3 = time.Now()
time.Sleep(3 * time.Second)
wg.Done()
}(&wg)

wg.Wait()

fmt.Println(r1, r2, r3)
fmt.Printf("took: %v\n", time.Since(start))
}

[xastley]

When you demonstrated channels, I think you can make(chan string, size) so you can mimick the config you had with waitgroups. You'll only be expecting 3 messages into the channel and then close it.

[daltonyon]

Great class!!! Personally I learn a lot

[kevinz]

super clear and easy to understand thank u

[kangtran]

What's the color theme are you using?
Thanks

[CrayonEater]

Would it make sense to invert your example, pass the wg.Wait to your anonymous function and have the channel for on the main thread to get results back to main thread? I suppose you could also pass a slice to the function instead of the wg

[hebozhe]

I don't use channels unless something is asynchronous forever. I just sense I'm wasting code harvesting channel results, when mutexes allow for arbitrarily large expansions into accepted containers.

[ghoulbond]

Thanks Anthony, just a quick question

is it a possible to close the channel inside the go routine in this way

go func() {
for res := range resultch {
fmt.Println(res)
}

fmt.println()
close(resultch)
}()

if it is possible, is it considered a good practice?

[SaiyanJin]

but we need the the result inside the main, adding the the for loop inside a goroutine then we can't have the results in the main

[alexandrk]

Volume becomes lower and lower with every next video, please make it at least a little bit louder, it's becoming hard to listen. Thanks for your work.