Default parameter values in PowerShell - Mini Project: Build & Apply

Default parameter values

📖 Scenario: You are creating a simple PowerShell script to greet users. Sometimes users provide their name, and sometimes they don't. You want the script to say "Hello, Guest!" when no name is given.

🎯 Goal: Build a PowerShell function that uses a default parameter value to greet a user by name or greet "Guest" if no name is provided.

📋 What You'll Learn

Create a function named Greet-User with a parameter Name that has a default value of 'Guest'.

Inside the function, output the greeting: Hello, <Name>! using the parameter value.

Call the function twice: once without any argument and once with the argument 'Alice'.

Print the output of both calls.

💡 Why This Matters

🌍 Real World

Scripts often need to handle missing information gracefully. Using default parameter values lets scripts run smoothly without requiring all inputs every time.

💼 Career

Knowing how to use default parameters is essential for writing flexible automation scripts, which is a common task in IT, DevOps, and system administration roles.

1

Create the function with a default parameter

Write a PowerShell function named Greet-User with a parameter Name that has the default value 'Guest'.

PowerShell

# Your code here

Need a hint?

Use the param block inside the function to define parameters with default values.

2

Add greeting output inside the function

Inside the Greet-User function, add a line to output the greeting Hello, <Name>! using the parameter Name.

PowerShell

function Greet-User {
    param(
        [string]$Name = 'Guest'
    )
    # Your code here
}

Need a hint?

Use Write-Output with a double-quoted string and the $Name variable inside.

3

Call the function with and without arguments

Call the Greet-User function twice: once without any argument and once with the argument 'Alice'.

PowerShell

function Greet-User {
    param(
        [string]$Name = 'Guest'
    )
    Write-Output "Hello, $Name!"
}

# Your code here

Need a hint?

Call the function by its name alone for default, and with -Name 'Alice' for a custom name.

4

Print the greetings from the function calls

Run the script so it prints the greetings from both calls to Greet-User. The output should show Hello, Guest! and Hello, Alice! on separate lines.

PowerShell

function Greet-User {
    param(
        [string]$Name = 'Guest'
    )
    Write-Output "Hello, $Name!"
}

Greet-User
Greet-User -Name 'Alice'

# Your code here

Need a hint?

Just run the script as is. The function calls already print the greetings.