一句話總結：channel空間不夠儲存到其他地方，等有空間再儲存儘量

package main

import "fmt"

func main() {

    memoryMsgChan := make(chan int, 4)
    s := []int{1,2,3,4,5,6,7}
    for _, msg := range s {
        select {
        case memoryMsgChan <- msg:
        default:
            fmt.Println("chan full:", msg)
        }
    }

    var
 
 a int = 11
    for i:=0; i<5;i++  {
        select {
        case a = <-memoryMsgChan:
            fmt.Println("a:", a)
        default:
            fmt.Println("chan empty")
        }
    }
}

chan full: 5
chan full: 6
chan full: 7
a: 1
a: 2
a: 3
a: 4
chan empty

Process finished with exit code 0