Summary - Select
- Go course
- Intermediate
- Lesson 18/80
- 4 min
Combine select, timeout and close to write a scheduler.
Summary - Select
In this section you learned select:
- Wait on many channels with select and fair picking
- Non-blocking with default for event loops
- Timeout with time.After to prevent forever waits
- Close a channel with close and end range
Now you will combine these to write a scheduler: select, timeout and close together.
Practice Write a scheduler
Inside main, add a select { case ... default: ... } block and print scheduler 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)
select {
case m := <-ch:
fmt.Println(m)
default:
fmt.Println("zamanlayıcı")
}
}Expected output
zamanlayıcı
Practice Scheduler output
Inside main, print select scheduler with fmt.Println.
Starter code
package main
import "fmt"
func main() {
// buraya yaz
}Sample solution
package main
import "fmt"
func main() {
fmt.Println("select scheduler")
}Expected output
select scheduler
Questions and answers
Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.
1 select usage
Question
select {
case v := <-ch:
fmt.Println(v)
____:
fmt.Println("zaman aşımı")
}
Answer
select {
case v := <-ch:
fmt.Println(v)
case <-time.After(1e9):
fmt.Println("zaman aşımı")
}Explanation: time.After returns a channel; case waits on it.
2 Match section concepts
| Term | Meaning |
|---|---|
select |
Multi-wait |
default |
Non-blocking |
time.After |
Timeout |
close |
Close |