Golang Program to Show the Duplicate Case Error in Switch Statement

A switch’s case must have a unique value. When repeated value is checked against the entire switch. The “duplicate case” error is arised. Let us discuss duplicate case error with the help of the examples:

Example 1:  

Go

// Golang program that causes
// duplicate case error

package main

import "fmt"

// Main function
func main() {
    value := 4

    // Duplicate cases are not allowed.
    switch value {
    case 4:
        fmt.Println(true)
    case 4:
        fmt.Println(true)
    }
}

Output:

./prog.go:15:10: duplicate case 4 in switch
    previous case at ./prog.go:13:10

Example 2:

Go

// Golang program that causes
// duplicate case error

package main

import "fmt"

// Main function
func main() {
    i := 1
    switch i {
        case 0, 1:
            fmt.Println("GeeksForGeeks")
            fallthrough
        case 0:
            fmt.Println("Geeks_0")
        case 1:
            fmt.Println("Geeks_1")
        default:
            fmt.Println("Number_of_Users")
    }
}

Output:

./prog.go:15:8: duplicate case 0 in switch
    previous case at ./prog.go:12:8
./prog.go:17:8: duplicate case 1 in switch
    previous case at ./prog.go:12:11