Function definition in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell function call?

Consider this PowerShell function definition and call:

function Get-Square {
  param($number)
  return $number * $number
}

Get-Square 4

PowerShell

function Get-Square {
  param($number)
  return $number * $number
}

Get-Square 4

A 16

B 4

C Error: Missing return statement

D 8

💡 Hint

Think about what multiplying a number by itself means.

The function Get-Square takes a number and returns its square. Calling Get-Square 4 returns 4 * 4 = 16.

📝 Syntax

intermediate

Which option correctly defines a PowerShell function with two parameters?

Select the correct syntax for a PowerShell function named 'Add-Numbers' that takes two parameters and returns their sum.

A function Add-Numbers { param($a, $b) return $a + $b }

B function Add-Numbers($a, $b) { return $a + $b }

C function Add-Numbers { $a, $b param; return $a + $b }

D function Add-Numbers { param $a $b; return $a + $b }

💡 Hint

Remember the param block syntax inside a function.

Option A correctly uses 'param' with parentheses and commas to define two parameters inside the function block.

🔧 Debug

advanced

Why does this PowerShell function fail to return the expected value?

Look at this function and its call:

function Multiply {
  param($x, $y)
  $result = $x * $y
}

Multiply 3 5

PowerShell

function Multiply {
  param($x, $y)
  $result = $x * $y
}

Multiply 3 5

A The parameters are not defined correctly; they need types.

B The function does not have a return statement, so it returns nothing.

C The multiplication operator '*' is invalid in PowerShell.

D The function name 'Multiply' is a reserved keyword.

💡 Hint

Think about what PowerShell functions output by default.

PowerShell functions output whatever is written to the pipeline. Since $result is assigned but not output or returned, the function returns nothing.

🚀 Application

advanced

What is the output of this PowerShell function with default parameter?

Given this function and call:

function Greet {
  param($name = 'Friend')
  "Hello, $name!"
}

Greet

PowerShell

function Greet {
  param($name = 'Friend')
  "Hello, $name!"
}

Greet

A Error: Missing argument for parameter 'name'

B Hello, $name!

C Hello, !

D Hello, Friend!

💡 Hint

What happens if you call a function without giving a value for a parameter with a default?

The parameter 'name' has a default value 'Friend'. Calling Greet without arguments uses this default, so it outputs 'Hello, Friend!'.

🧠 Conceptual

expert

What is the value of $result after running this PowerShell script?

Analyze this script:

function Test-Output {
  param($val)
  if ($val -gt 10) { return 'High' }
  'Low'
}

$result = Test-Output 5

PowerShell

function Test-Output {
  param($val)
  if ($val -gt 10) { return 'High' }
  'Low'
}

$result = Test-Output 5
$result

A $null

B 'High'

C 'Low'

D 5

💡 Hint

Consider what happens when the if condition is false and the function reaches the last line.

If $val is not greater than 10, the function does not return inside the if block, so it outputs the last line 'Low'.