Switch statement in Go - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple switch statement

What is the output of this Go program?

Go

package main
import "fmt"
func main() {
  x := 2
  switch x {
  case 1:
    fmt.Println("One")
  case 2:
    fmt.Println("Two")
  case 3:
    fmt.Println("Three")
  default:
    fmt.Println("Other")
  }
}

A Two

B Three

C One

D Other

💡 Hint

Look at the value of x and which case matches it.

The variable x is 2, so the switch matches case 2 and prints "Two".

❓ Predict Output

intermediate

Switch with multiple cases and fallthrough

What will this Go program print?

Go

package main
import "fmt"
func main() {
  n := 1
  switch n {
  case 1:
    fmt.Println("One")
    fallthrough
  case 2:
    fmt.Println("Two")
  case 3:
    fmt.Println("Three")
  default:
    fmt.Println("Default")
  }
}

A

One
Two
Three

B Two

C

One
Two

D One

💡 Hint

Remember that fallthrough makes the next case run too.

The switch matches case 1 and prints "One". The fallthrough causes case 2 to run next, printing "Two".

❓ Predict Output

advanced

Switch with expression and no matching case

What is the output of this Go program?

Go

package main
import "fmt"
func main() {
  x := 10
  switch {
  case x < 5:
    fmt.Println("Less than 5")
  case x > 20:
    fmt.Println("Greater than 20")
  default:
    fmt.Println("Between 5 and 20")
  }
}

A Between 5 and 20

B Greater than 20

C Less than 5

D No output

💡 Hint

The switch has no expression, so it checks each case condition as a boolean.

x is 10, so x < 5 is false, x > 20 is false, so default runs printing "Between 5 and 20".

❓ Predict Output

advanced

Switch with type assertion

What will this Go program print?

Go

package main
import "fmt"
func main() {
  var i interface{} = 3.14
  switch v := i.(type) {
  case int:
    fmt.Println("int", v)
  case float64:
    fmt.Println("float64", v)
  case string:
    fmt.Println("string", v)
  default:
    fmt.Println("unknown")
  }
}

A int 3

B float64 3.14

C unknown

D string 3.14

💡 Hint

The variable i holds a float64 value, so the type switch matches float64.

The type assertion switch matches float64 and prints "float64 3.14".

🧠 Conceptual

expert

Behavior of fallthrough in switch with multiple cases

Consider this Go code snippet: var x = 2 switch x { case 1, 2: fmt.Println("One or Two") fallthrough case 3: fmt.Println("Three") case 4: fmt.Println("Four") } What will be printed when this code runs?

A

One or Two
Three
Four

B One or Two

C Three

D

One or Two
Three

💡 Hint

fallthrough only moves to the next case, even if it has multiple values.

The switch matches case 1,2 and prints "One or Two". The fallthrough causes case 3 to run next, printing "Three". Case 4 does not run.