Breaking News: Grepper is joining You.com. Read the official announcement!

golang channel example

Add Answer

Restu Wahyu Saputra answered on April 18, 2022 Popularity 3/10 Helpfulness 1/10

answer golang channel example

related golang channel

related golang channels example

related golang channel

related golang channels example

related golang channel

golang channel example

Comment

package main

import (
	"time"
	"math/rand"
	"fmt"
)

func longTimeRequest() <-chan int32 {
	r := make(chan int32)

	go func() {
		// Simulate a workload.
		time.Sleep(time.Second * 3)
		r <- rand.Int31n(100)
	}()

	return r
}

func sumSquares(a, b int32) int32 {
	return a*a + b*b
}

func main() {
	rand.Seed(time.Now().UnixNano())

	a, b := longTimeRequest(), longTimeRequest()
	fmt.Println(sumSquares(<-a, <-b))
}

Popularity 3/10 Helpfulness 1/10 Language go

Source: go101.org

Tags: channel go

Link to this answer
Share Copy Link

Contributed on Sep 25 2022

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

Closely Related Answers

golang channel

Comment

// When we send data into the channel using a GoRoutine, 
// it will be blocked until the data is consumed by another GoRoutine.

// When we receive data from channel using a GoRoutine, 
// it will be blocked until the data is available in the channel.

func main() {
	runIncrement()
}

func runIncrement() {
	channel := make(chan string)

	go increment(channel)
	time.Sleep(1 * time.Second)

	for msg := range channel {
		fmt.Println(msg)
	}
}

func increment(channel chan string) {
	for i := 0; i < 3; i++ {
		channel <- "Hello Wordl"
	}
	time.Sleep(1 * time.Second)
	close(channel)
}

func runCounter() {
	channel := make(chan string)
	wg := sync.WaitGroup{}

	wg.Add(1)
	go counter(channel, &wg)

	for msg := range channel {
		fmt.Println(msg)
	}
	wg.Wait()
}

func counter(channel chan string, wg *sync.WaitGroup) {
	for i := 0; i < 3; i++ {
		channel <- "Hello world"
	}
	wg.Done()
	close(channel)
}

Popularity 10/10 Helpfulness 3/10 Language go

Source: Grepper

Tags: channel

Link to this answer
Share Copy Link

Contributed on Apr 18 2022

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channels example

Comment

package main

import (
	"fmt"
)

func overwrite(n chan int) {
	<-n
	n <- 2021
	c := <-n
	fmt.Println(c)
}

func main() {
	ch := make(chan int, 1)
	ch <- 2022
	overwrite(ch)
}

Popularity 9/10 Helpfulness 2/10 Language go

Source: Grepper

Tags: channels channel

Link to this answer
Share Copy Link

Contributed on Sep 26 2022

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channel

Comment

package main

import (
	"fmt"
	"time"
)

func main() {
	channelImmutable()
}

// -> you use only allow one channel capacity, but you use 2 capacity, channel can be blocked
// for handle this issue, you must create channel to zero value, like this <- ch
func channelImmutable() {
	ch := make(chan string, 1)
	ch <- "marwan"
	<-ch
	ch <- "jajang"

	fmt.Println("channelOne", <-ch) // and i can print jajang not marwan and this can't be blocked
}

// channelOne print value, with declare to variable channel;
func channelOne() {
	ch := make(chan string, 2)
	ch <- "marwan"
	ch <- "jajang"

	fmt.Println("channelOne", <-ch)
	fmt.Println("channelOne", <-ch)
}

// channelTwo print value and wrapper with gorutine, because with you use loop range not using gorutine channel is blocked, because you print more channel
func channelTwo() {
	ch := make(chan string, 2)
	ch <- "marwan"
	ch <- "jajang"

	go func() {
		for v := range ch {
			fmt.Println(v)
		}
	}()
	time.Sleep(time.Second * 1)
}

// channelThree print value without gorutine, but with loop and length channel
func channelThree() {
	ch := make(chan string, 2)
	ch <- "marwan"
	ch <- "jajang"

	for i := 0; i <= len(ch); i++ {
		fmt.Println(<-ch)
	}
}

Popularity 6/10 Helpfulness 2/10 Language go

Source: Grepper

Tags: channel go

Link to this answer
Share Copy Link

Contributed on Mar 04 2024

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channels example

Comment

package main

import (
	"fmt"
	"time"
)

func main() {
	// channel with capacity of 2
	message := make(chan string, 2)

	go func() {
		message <- "ping 1"
		message <- "ping 2"
		message <- "ping 3"
	}()

	go func() {
		time.Sleep(time.Second)
		defer close(message)
	}()

	for msg := range message {
		fmt.Println(msg)
	}

}

Popularity 8/10 Helpfulness 2/10 Language go

Source: Grepper

Tags: channels channel

Link to this answer
Share Copy Link

Contributed on Sep 26 2022

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channel

Comment

package main

import (
	"errors"
	"fmt"
	"log"
	"time"
)

// anda dapat mencetak nilai setelah gorutine itu selesai process nya, ganti time.Sleep dengan sync.WaitGroup
func main() {
	SuccessOne()
}

func SuccessOne() {
	resChan := make(chan string, 1)
	errChan := make(chan error, 1)

	go func(chRes chan string, chErr chan error) {
		perkalian := 2 * 2

		if perkalian == 4 {
			chRes <- "Success"
		} else {
			chErr <- errors.New("Failed")
		}

	}(resChan, errChan)

	time.Sleep(time.Second * 1)

	select {
	case err := <-errChan:
		if err != nil {
			log.Fatal(err)
		}

	case res := <-resChan:
		if res != "" {
			fmt.Println(res)
		}

	default:
		fmt.Println("Not received channel")
	}
}

func SuccessTwo() {
	resChan := make(chan string, 1)
	errChan := make(chan error, 1)

	go func(chRes chan string, chErr chan error) {
		perkalian := 2 * 2

		if perkalian == 4 {
			defer close(chErr)
			chRes <- "Success"
		} else {
			defer close(chRes)
			chErr <- errors.New("Failed")
		}

	}(resChan, errChan)

	time.Sleep(time.Second * 1)

	if err := <-errChan; err != nil {
		log.Fatal(err)
	}

	fmt.Println(<-resChan)
}

func SuccessThree() {
	resChan := make(chan string, 1)
	errChan := make(chan error, 1)

	go func(chRes chan string, chErr chan error) {
		perkalian := 2 * 2

		if perkalian == 4 {
			chErr <- nil
			chRes <- "Success"
		} else {
			chRes <- ""
			chErr <- errors.New("Failed")
		}

	}(resChan, errChan)

	time.Sleep(time.Second * 1)

	if err := <-errChan; err != nil {
		log.Fatal(err)
	}

	fmt.Println(<-resChan)
}

// dikarenakan perkalian nilainya sama dengan 4 dan chRes menerima nilai success, 
// tetapi chErr tidak menerima nilai dan ini mengakibatkan chErr melakukan pemblokiran, karena channel nya selalu open dan nilainya kosong
// jadi dia harus di tutup atau di beri nilai atau menugnakan select untuk memilih channel mana yang memiliki nilai, untuk menghindari pemblokiran

func WrongCode() {
	resChan := make(chan string, 1)
	errChan := make(chan error, 1)

	go func(chRes chan string, chErr chan error) {
		perkalian := 2 * 2

		if perkalian == 4 {
			chRes <- "Success"
		} else {
			chErr <- errors.New("Failed")
		}

	}(resChan, errChan)

	time.Sleep(time.Second * 1)

	if err := <-errChan; err != nil {
		log.Fatal(err)
	}

	fmt.Println(<-resChan)
}

Popularity 6/10 Helpfulness 1/10 Language go

Source: Grepper

Tags: channel go

Link to this answer
Share Copy Link

Contributed on Mar 04 2024

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channel

Comment

package main

import (
	"fmt"
	"time"
)

func main() {
	ch := make(chan string, 1)

	go func(chStr chan string) {
		chStr <- "Fuck Israel"
	}(ch)

	go func(chStr chan string) {
		fmt.Println(<-chStr)
		chStr <- "Free Palestine"
	}(ch)

	time.Sleep(time.Second * 1)

	fmt.Println(<-ch)
}

Popularity 6/10 Helpfulness 1/10 Language go

Source: Grepper

Tags: channel go

Link to this answer
Share Copy Link

Contributed on Mar 04 2024

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channel

Comment

// if you use channel inside gorutine can't use defer in wg
// because this is deadlock, because channel is async process
// if you use channel, for better experience pass channel into params gorutine

package main

import (
	"fmt"
	"sync"
)

func main() {
	wg := sync.WaitGroup{}
	ch := make(chan int)

	wg1 := sync.WaitGroup{}
	slc := []int{}

	for i := 0; i < 5; i++ {
		wg.Add(1)
		go func(chInt chan int) {
			wg.Done()
			chInt <- i

		}(ch)

	}
	wg.Wait()

	for i := 0; i < 5; i++ {
		wg1.Add(1)
		go func() {
			defer wg1.Done()
			slc = append(slc, i)

		}()
	}
	wg1.Wait()

	fmt.Println(<-ch)
	fmt.Println(slc)
}

Popularity 5/10 Helpfulness 1/10 Language go

Source: Grepper

Tags: channel go

Link to this answer
Share Copy Link

Contributed on Mar 05 2024

Restu Wahyu Saputra

0 Answers Avg Quality 2/10

golang channel example

Contents

More Related Answers

golang channel example

Closely Related Answers

golang channel

golang channels example

golang channel

golang channels example

golang channel

golang channel

golang channel

Grepper

Documentation

Social

Legal

Contact

Oops, You will need to install Grepper and log-in to perform this action.