Default parameter values in PowerShell - Cheat Sheet & Quick Revision

Recall & Review

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What is a default parameter value in PowerShell functions?

A default parameter value is a value assigned to a function parameter that is used if no argument is provided when the function is called. It helps avoid errors and makes parameters optional.

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How do you define a default value for a parameter in a PowerShell function?

You assign the default value directly in the parameter declaration using the equals sign, like: param([string]$name = "Guest").

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Why are default parameter values useful in scripting?

They make functions easier to use by allowing callers to skip parameters when the default is fine. This reduces the need to always specify every argument.

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What happens if you call a PowerShell function without providing a value for a parameter that has a default?

The function uses the default value assigned to that parameter automatically.

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Show a simple PowerShell function with a default parameter value and explain its output when called with and without an argument.

Example: function Greet { param([string]$name = "Friend") "Hello, $name!" } Calling Greet returns "Hello, Friend!" because no argument was given. Calling Greet -name "Anna" returns "Hello, Anna!" because the argument overrides the default.

How do you assign a default value to a parameter in a PowerShell function?

A param([type]$param = value)

B param([type]$param: value)

C param([type]$param <- value)

D param([type]$param ? value)

In PowerShell, default values are assigned using the equals sign (=) inside the param block.

What happens if you call a function without specifying a parameter that has a default value?

A The function throws an error.

B The function uses the default value for that parameter.

C The function ignores the parameter.

D The function waits for user input.

If a parameter has a default value, PowerShell uses it when no argument is provided.

Why use default parameter values in scripts?

A To make parameters mandatory.

B To slow down the script.

C To allow skipping parameters when defaults are fine.

D To confuse users.

Default values let users call functions without specifying every parameter.

Which of these is a correct default parameter declaration in PowerShell?

A param([int]$count = 5)

B param([int]$count == 5)

C param([int]$count : 5)

D param([int]$count <- 5)

Only the equals sign (=) is valid for default values in PowerShell parameters.

If a function parameter has a default value, can you still provide a different value when calling the function?

A Only if the parameter is mandatory.

B No, the default always overrides.

C Only if the default is null.

D Yes, the provided value replaces the default.

Providing an argument overrides the default value.

Explain how to use default parameter values in a PowerShell function and why they are helpful.

Think about how to make parameters optional with a fallback value.

Write a simple PowerShell function with a default parameter and describe what happens when you call it with and without that parameter.

Use param block and assign a default value.