Receiving data
- Go course
- Intermediate
- Lesson 10/80
- 4 min
Learn to receive data from a channel with <-.
Receiving data
To receive from a channel use the same <- operator: v := <-ch. This takes a value from ch and assigns it to v. In an unbuffered channel it blocks until a sender is ready.
The receive expression is v := <-ch. The arrow points out of the channel. You can print directly with fmt.Println(<-ch). A closed channel returns the zero value.
Receive and block
In an unbuffered channel the receiver blocks until a sender is ready. This makes the channel a synchronization tool: both wait until they meet.
With v, ok := <-ch you learn whether the channel is open or closed. If ok is false the channel is closed and drained. This pattern detects channel closure.
Practice Receive from a channel
Inside main, add a <-ch expression and print received with fmt.Println.
Starter code
package main
import "fmt"
func main() {
// buraya yaz
}Sample solution
package main
import "fmt"
func main() {
ch := make(chan string)
go func() { ch <- "alındı" }()
fmt.Println(<-ch)
}Expected output
alındı
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 What does v := <-ch do?
- Closes ch
- Receives from ch into v Correct answer
- Deletes v
- Sends v on ch
Explanation: receives from ch into v. Sending is ch <- v.
2 Receive expression
v := ____chv := <-chExplanation: The same operator is used for send and receive.
3 Match receive concepts
| Term | Meaning |
|---|---|
<-ch |
Receive |
v, ok |
Status check |
block |
Wait |
closed |
Zero value |