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