As we know that a channel is a medium of communication between concurrently running goroutines so that they can send and receive data to each other. By default a channel is bidirectional but you can create a unidirectional channel also. A channel that can only receive data or a channel that can only send data is the unidirectional channel. The unidirectional channel can also create with the help of make() function as shown below:
// Only to receive data c1:= make(<- chan bool) // Only to send data c2:= make(chan<- bool)
Example 1:
// Go program to illustrate the concept // of the unidirectional channel package main
import "fmt"
// Main function func main() {
// Only for receiving
mychanl1 := make(<- chan string )
// Only for sending
mychanl2 := make( chan <- string )
// Display the types of channels
fmt.Printf("%T", mychanl1)
fmt.Printf("\n%T", mychanl2)
} |
Output:
<-chan string chan<- string
Converting Bidirectional Channel into the Unidirectional Channel
In Go language, you are allowed to convert a bidirectional channel into a unidirectional channel, or in other words, you can convert a bidirectional channel into a receive-only or send-only channel, but vice versa is not possible. As shown in the below program:
Example:
// Go program to illustrate how to convert // bidirectional channel into the // unidirectional channel package main
import "fmt"
func sending(s chan <- string ) {
s <- "GeeksforGeeks"
} func main() {
// Creating a bidirectional channel
mychanl := make( chan string )
// Here, sending() function convert
// the bidirectional channel
// into send only channel
go sending(mychanl)
// Here, the channel is sent
// only inside the goroutine
// outside the goroutine the
// channel is bidirectional
// So, it print GeeksforGeeks
fmt.Println(<-mychanl)
} |
Output:
GeeksforGeeks
Use of Unidirectional Channel: The unidirectional channel is used to provide the type-safety of the program so, that the program gives less error. Or you can also use a unidirectional channel when you want to create a channel that can only send or receive data.