// _Switch statements_ express conditionals across many // branches. package main import "fmt" import "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 the type of an interface // value. In this example, the variable `t` will have the // type corresponding to its clause. whatAmI := func(i interface{}) string { switch t := i.(type) { case bool: return "I am a bool" case int: return "I am an int" default: return fmt.Sprintf("Can't handle type %T", t) } } fmt.Println(whatAmI(1)) fmt.Println(whatAmI(true)) fmt.Println(whatAmI("hey")) }