What is Go Language switch?

 The Go switch statement executes one statement from multiple conditions. It is similar to if-else-if chain statement.

Syntax:

1. switch  var1 {  
2. case val1:  
3. .....  
4. case val2  
5. .....  
6. default:  
7. .....  
8. }  

The switch statement in Go is more flexible. In the above syntax, var1 is a variable which can be of any type, and val1, val2, ... are possible values of var1.

In switch statement, more than one values can be tested in a case, the values are presented in a comma separated list

like: case val1, val2, val3:

If any case is matched, the corresponding case statement is executed. Here, the break keyword is implicit. So automatic fall-through is not the default behavior in Go switch statement.

For fall-through in Go switch statement, use the keyword "fallthrough" at the end of the branch.

Go Switch Example:

1. package main  
2. import "fmt"  
3. func main() {  
4.    fmt.Print("Enter Number: ")  
5.   var input int  
6.   fmt.Scanln(&input)  
7.    switch (input) {  
8.   case 10:  
9.       fmt.Print("the value is 10")  
10.     case 20:  
11.       fmt.Print("the value is 20")  
12.     case 30:  
13.       fmt.Print("the value is 30")  
14.     case 40:  
15.       fmt.Print("the value is 40")  
16.     default:  
17.       fmt.Print(" It is not 10,20,30,40 ")  
18.    }  
19. }  

Output:

Enter Number: 20
the value is 20

or

Output:

Enter Number: 35
 It is not 10,20,30,40

Go switch fallthrough example

1. import "fmt"  
2. func main() {  
3.    k := 30  
4.    switch k {  
5.    case 10:  
6.       fmt.Println("was <= 10"); fallthrough;  
7.    case 20:  
8.       fmt.Println("was <= 20"); fallthrough;  
9.    case 30:  
10.       fmt.Println("was <= 30"); fallthrough;  
11.    case 40:  
12.       fmt.Println("was <= 40"); fallthrough;  
13.    case 50:  
14.       fmt.Println("was <= 50"); fallthrough;  
15.    case 60:  
16.       fmt.Println("was <= 60"); fallthrough;  
17.    default:  
18.       fmt.Println("default case")  
19.    }  
20. }  

Output:

was <= 30
was <= 40
was <= 50
was <= 60
default case