// _Switch statements_ express conditionals across many // branches. package main import ( "fmt" "time" ) func main() { // Here's a basic `switch`. i := 2 fmt.Print("Write ", i, " as ") switch i { case 1: fmt.Println("one") case 2: fmt.Println("two") case 3: fmt.Println("three") } // You can use commas to separate multiple expressions // in the same `case` statement. We use the optional // `default` case in this example as well. switch time.Now().Weekday() { case time.Saturday, time.Sunday: fmt.Println("It's the weekend") default: fmt.Println("It's a weekday") } // `switch` without an expression is an alternate way // to express if/else logic. Here we also show how the // `case` expressions can be non-constants. t := time.Now() switch { case t.Hour() < 12: fmt.Println("It's before noon") default: fmt.Println("It's after noon") } // A type `switch` compares types instead of values. You // can use this to discover the type of an interface // value. In this example, the variable `t` will have the // type corresponding to its clause. 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("hey") }