Go Switch Statement

In this tutorial you will learn about the Go Switch Statement and its application with practical example.

The switch statement is simplified form of the nested if … else if statement , it avoids long chain of if..else if..else statements. A switch statement evaluates an expression against multiple cases in order to identify the block of code to be executed.

Table Of Contents−

Go Switch Statement
Go Switch fallthrough

Go Switch with a short statement
Go switch with no expression

Syntax:-

switch <expression>{
case <val1>:
  //Block of code to be executed if expression = val1;
case <val2>:
  //Block of code to be executed if expression = val2;
default:
  //Optional
  //Block of code to be executed
  //if expression is different 
  //from both val1 and val2;
}

switch <expression>{

case <val1>:

//Block of code to be executed if expression = val1;

case <val2>:

//Block of code to be executed if expression = val2;

default:

//Optional

//Block of code to be executed

//if expression is different

//from both val1 and val2;

}

Example:-

package main
import "fmt"
func main() {

	var dayOfWeek = 5
	fmt.Println("W3Adda - Go switch statement.")
	switch dayOfWeek {
	case 1:
		fmt.Println("Today is Monday.")
	case 2:
		fmt.Println("Today is Tuesday.")
	case 3:
		fmt.Println("Today is Wednesday.")
	case 4:
		fmt.Println("Today is Thursday.")		
	case 5:
		fmt.Println("Today is Friday.")
	case 6:
		fmt.Println("Today is Saturday.")	
	case 7:
		fmt.Println("Today is Sunday.")	
	default:
		fmt.Println("Invalid Weekday.")
	}

}

package main

import "fmt"

func main() {

var dayOfWeek = 5

fmt.Println("W3Adda - Go switch statement.")

switch dayOfWeek {

case 1:

fmt.Println("Today is Monday.")

case 2:

fmt.Println("Today is Tuesday.")

case 3:

fmt.Println("Today is Wednesday.")

case 4:

fmt.Println("Today is Thursday.")

case 5:

fmt.Println("Today is Friday.")

case 6:

fmt.Println("Today is Saturday.")

case 7:

fmt.Println("Today is Sunday.")

default:

fmt.Println("Invalid Weekday.")

}

Output:-

go_switch_statement_1

In Go, you can have multiple values in a single case statement separated with comma (,) as following –

Example :-

package main
import "fmt"
func main() {

	var dayOfWeek = 5
	fmt.Println("W3Adda - Go switch with multiple case combnied.")
	switch dayOfWeek {
		case 1, 2, 3, 4, 5:
			fmt.Println("It's a Weekday.")
		case 6, 7:
			fmt.Println("Its Weekend.")
		default:
			fmt.Println("Invalid Day")		
	}

}

package main

import "fmt"

func main() {

var dayOfWeek = 5

fmt.Println("W3Adda - Go switch with multiple case combnied.")

switch dayOfWeek {

case 1, 2, 3, 4, 5:

fmt.Println("It's a Weekday.")

case 6, 7:

fmt.Println("Its Weekend.")

default:

fmt.Println("Invalid Day")

}

Output:-

go_switch_statement_2

Go Switch fallthrough

In switch statement a fallthrough statement allows to execute all the following statements after a match found.

Example:-

package main
import "fmt"
func main() {

	var x = 2
	fmt.Println("W3Adda - Go switch with fallthrough.")
	switch x {
	case 1:
	fmt.Println("1")
	fallthrough
	case 2:
	fmt.Println("2")
	fallthrough
	case 3:
	fmt.Println("3")
	}

}

package main

import "fmt"

func main() {

var x = 2

fmt.Println("W3Adda - Go switch with fallthrough.")

switch x {

case 1:

fmt.Println("1")

fallthrough

case 2:

fmt.Println("2")

fallthrough

case 3:

fmt.Println("3")

}

Output:-

go_switch_fallthrough

Go Switch with a short statement

In Go, a switch statement can also contain a short declaration statement like the If statement before the conditional expression as following –

Example:-

package main
import "fmt"
func main() {

	fmt.Println("W3Adda - Go switch with short statement.")
	switch dayOfWeek := 5; dayOfWeek {
		case 1, 2, 3, 4, 5:
			fmt.Println("It's a Weekday.")
		case 6, 7:
			fmt.Println("Its Weekend.")
		default:
			fmt.Println("Invalid Day")		
	}

}

package main

import "fmt"

func main() {

fmt.Println("W3Adda - Go switch with short statement.")

switch dayOfWeek := 5; dayOfWeek {

case 1, 2, 3, 4, 5:

fmt.Println("It's a Weekday.")

case 6, 7:

fmt.Println("Its Weekend.")

default:

fmt.Println("Invalid Day")

}

Output:-

go_switch_with_short_statement

Go switch with no expression

Syntax:-

switch {
    case <boolean_expression_2>:
        //do something
    case <boolean_expression_2>:
        //do something
}

switch {

case <boolean_expression_2>:

//do something

case <boolean_expression_2>:

//do something

}

Example:-

package main
import "fmt"

func main() {
	var marks = 55 
	fmt.Println("W3Adda - Go switch with no expression.")
	switch {
		case marks > 60:
			fmt.Println("Passed with 'A' Grade")
		case marks < 60 && marks >=50:
			fmt.Println("Passed with 'B' Grade")
		case marks < 50 && marks >= 35:
			fmt.Println("Passed with 'C' Grade")
		default:
			fmt.Println("You're Fail")	
	}
}

package main

import "fmt"

func main() {

var marks = 55

fmt.Println("W3Adda - Go switch with no expression.")

switch {

case marks > 60:

fmt.Println("Passed with 'A' Grade")

case marks < 60 && marks >=50:

fmt.Println("Passed with 'B' Grade")

case marks < 50 && marks >= 35:

fmt.Println("Passed with 'C' Grade")

default:

fmt.Println("You're Fail")

}

Output:-

go_switch_no_expression

Note:- In Go, a break statement can be used to inside your matched case to exit the switch statement.

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Go Switch Statement