Overview

The select statement only executes one of the cases on which either send or receive channel operation is ready. It cannot execute multiple cases but there is a workaround to it. We can have a for loop outside the set statement. This for loop will call the select statement equal to the number of iterations in the loop.

Let’s see an example.

Code

package main
import "fmt"
func main() {
ch1 := make(chan string)
ch2 := make(chan string)
go goOne(ch1)
go goTwo(ch2)
for i := 0; i < 2; i++ {
select {
case msg1 := <-ch1:
fmt.Println(msg1)
case msg2 := <-ch2:
fmt.Println(msg2)
}
}
}
func goOne(ch chan string) {
ch <- "From goOne goroutine"
}
func goTwo(ch chan string) {
ch <- "From goTwo goroutine"
}

Output

From goOne goroutine
From goTwo goroutine

In the above program we put a for loop of length two across the select statement. Hence the select statement is executed twice and prints the received value from each of the case statement.

This way we can execute multiple case statement but do note that it is not deterministic. If there are multiple operations available on the same channel for a particular case statement then that case can be executed every time in all iterations of the for loop