Switch expression behavior in Go - Mini Project: Build & Apply

Switch Expression Behavior in Go

📖 Scenario: You are building a simple program to identify the type of day based on a number. This is like checking the day of the week where numbers 1 to 7 represent Monday to Sunday.

🎯 Goal: Learn how to use a switch expression in Go to print the correct day name for a given number.

📋 What You'll Learn

Create a variable dayNumber with an integer value

Create a switch expression using dayNumber

Use case statements for numbers 1 to 7 with corresponding day names

Use default case to handle invalid numbers

Print the day name or an error message

💡 Why This Matters

🌍 Real World

Switch statements are used in many programs to choose actions based on user input or data values, like menus or commands.

💼 Career

Understanding switch expressions is important for writing clear and efficient decision-making code in Go, useful in backend development and system programming.

1

Create the day number variable

Create an integer variable called dayNumber and set it to 3.

Go

# Create the variable dayNumber and set it to 3
# Your code here

Need a hint?

Use := to declare and assign the variable in one step.

2

Start the switch expression

Add a switch expression using the variable dayNumber inside the main function.

Go

package main

func main() {
    dayNumber := 3
    // Start a switch expression on dayNumber
    // Your code here
}

Need a hint?

Write switch dayNumber { to start the switch expression.

3

Add cases for days 1 to 7 and default

Inside the switch dayNumber, add case statements for numbers 1 to 7. For each case, use fmt.Println to print the day name: "Monday" for 1, "Tuesday" for 2, "Wednesday" for 3, "Thursday" for 4, "Friday" for 5, "Saturday" for 6, and "Sunday" for 7. Add a default case that prints "Invalid day number".

Go

package main

import "fmt"

func main() {
    dayNumber := 3
    switch dayNumber {
        // Add cases 1 to 7 with fmt.Println for day names
        // Add default case for invalid day
        // Your code here
    }
}

Need a hint?

Each case ends with a colon and the code to run is indented below it.

4

Run and print the output

Run the program and print the output. The program should print the day name for dayNumber = 3.

Go

package main

import "fmt"

func main() {
    dayNumber := 3
    switch dayNumber {
    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")
    case 6:
        fmt.Println("Saturday")
    case 7:
        fmt.Println("Sunday")
    default:
        fmt.Println("Invalid day number")
    }

    // Your code here
}

Need a hint?

Run the program and check the output matches the expected day name.