Switch

Context

In Go, switch is very flexible:

• No implicit fallthrough (automatic break between cases).
• Cases can be lists of values.
• You can use a switch without an expression (equivalent to an if-else chain).
• fallthrough forces execution into the next case (rarely used).

Example

Determine the type of day, or use a switch without expression.

Code example

package main

import (
    "fmt"
    "time"
)

func main() {
    day := time.Now().Weekday()

    switch day {
    case time.Saturday, time.Sunday:
        fmt.Println("It's the weekend!")
    default:
        fmt.Println("It's a weekday.")
    }

    // Switch without expression
    x := 10
    switch {
    case x > 0:
        fmt.Println("x is positive")
    case x < 0:
        fmt.Println("x is negative")
    default:
        fmt.Println("x is zero")
    }

    // fallthrough (not recommended)
    a := 2
    switch a {
    case 1:
        fmt.Println("one")
    case 2:
        fmt.Println("two")
        fallthrough
    case 3:
        fmt.Println("three (fallthrough)")
    }
}

Output (example depends on current day)

It's a weekday.
x is positive
two
three (fallthrough)

Useful links

• Go spec: Switch statements
• Go by Example: Switch