Go Switch Statement

A switch statement tests a value against multiple cases and runs the matching block. It is a cleaner alternative to writing many if-else if chains when checking a single value against fixed options.

Basic Switch Statement

package main

import "fmt"

func main() {
    day := 3

    switch day {
    case 1:
        fmt.Println("Monday")
    case 2:
        fmt.Println("Tuesday")
    case 3:
        fmt.Println("Wednesday")
    case 4:
        fmt.Println("Thursday")
    case 5:
        fmt.Println("Friday")
    default:
        fmt.Println("Weekend")
    }
}

Output:

Wednesday

Switch Flow Diagram

         value = 3
              │
              ▼
        case 1? → No
              │
        case 2? → No
              │
        case 3? → Yes ──► "Wednesday"
              │
           (stops)

Go automatically stops after the first matching case. No break statement is needed — unlike C or Java.

Switch with String

package main

import "fmt"

func main() {
    lang := "Go"

    switch lang {
    case "Python":
        fmt.Println("You chose Python")
    case "Go":
        fmt.Println("You chose Go")
    case "Java":
        fmt.Println("You chose Java")
    default:
        fmt.Println("Unknown language")
    }
}

Output:

You chose Go

Multiple Values in One Case

Multiple values can be listed in a single case, separated by commas. If the tested value matches any of them, that case runs.

package main

import "fmt"

func main() {
    day := "Saturday"

    switch day {
    case "Saturday", "Sunday":
        fmt.Println("Weekend!")
    case "Monday", "Tuesday", "Wednesday", "Thursday", "Friday":
        fmt.Println("Weekday")
    }
}

Output:

Weekend!

Switch Without a Condition (Expression Switch)

When no value is given after switch, Go treats it like an if-else chain. Each case holds a boolean condition.

package main

import "fmt"

func main() {
    score := 82

    switch {
    case score >= 90:
        fmt.Println("Grade A")
    case score >= 75:
        fmt.Println("Grade B")
    case score >= 60:
        fmt.Println("Grade C")
    default:
        fmt.Println("Grade F")
    }
}

Output:

Grade B

Switch with Initialization

A variable can be declared directly inside the switch statement. It is scoped only to the switch block.

package main

import "fmt"

func getStatus() int {
    return 404
}

func main() {
    switch code := getStatus(); code {
    case 200:
        fmt.Println("OK")
    case 404:
        fmt.Println("Not Found")
    case 500:
        fmt.Println("Server Error")
    default:
        fmt.Println("Unknown Status")
    }
}

Output:

Not Found

The fallthrough Keyword

By default, Go stops at the first matching case. The fallthrough keyword forces execution to continue into the next case regardless of its condition.

package main

import "fmt"

func main() {
    level := 1

    switch level {
    case 1:
        fmt.Println("Beginner")
        fallthrough
    case 2:
        fmt.Println("Intermediate")
    case 3:
        fmt.Println("Advanced")
    }
}

Output:

Beginner
Intermediate

Switch vs if-else

Key Points

• Switch tests a value against multiple cases and runs the first match
• No break is needed — Go stops at the matching case automatically
• Multiple values fit in one case separated by commas
• Switch without a condition works like a chain of if-else conditions
• fallthrough forces execution to continue to the next case