switch.go

package main

import (
	"fmt"
	"time"
)

func main() {
	i := 2
	fmt.Println("write", i, "as")
	//only case
	switch i {
	case 0:
		fmt.Println("zero")
	case 1:
		fmt.Println("one")
	case 2:
		fmt.Println("two")
	case 3:
		fmt.Println("three")
	}
	// case and default
	switch time.Now().Weekday() {
	case time.Sunday, time.Saturday:
		fmt.Println("It's the weekend")
	default:
		fmt.Println("It's the weekday")
	}
	//swtich无参数
	t := time.Now()
	switch {
	case t.Hour() < 12:
		fmt.Println("It's before noon")
	default:
		fmt.Println("It's after noon")
	}

	whatAmI := func(i interface{}) {
		switch t := i.(type) {
		case bool:
			fmt.Println("I'm a bool")
		case int:
			fmt.Println("I'm an int")
		default:
			fmt.Printf("Don't know type , %T\n", t)
		}
	}

	whatAmI(true)
	whatAmI(1)
	whatAmI("hello")
}