Variable creation with $ in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell code?

Consider the following script:

$name = "Alice"
Write-Output $name

What will be printed when this script runs?

PowerShell

$name = "Alice"
Write-Output $name

A Write-Output Alice

B $name

C Alice

D Error: Variable not defined

💡 Hint

Variables in PowerShell start with $. The Write-Output command prints the value of the variable.

The variable $name holds the string "Alice". Write-Output prints the value stored in $name, so it outputs Alice.

📝 Syntax

intermediate

Which option correctly creates a variable with the value 10?

In PowerShell, you want to create a variable named $count with the number 10. Which line is correct?

A $count := 10

B $count = 10

C count = $10

D let $count = 10

💡 Hint

PowerShell uses = to assign values to variables starting with $.

In PowerShell, variables start with $ and assignment uses =. So $count = 10 is correct.

🔧 Debug

advanced

What error does this code produce?

Look at this script:

name = "Bob"
Write-Output $name

What error will occur when running it?

PowerShell

name = "Bob"
Write-Output $name

A Error: Variable 'name' is not recognized because it lacks $

B Outputs: Bob

C Error: Write-Output is not a recognized command

D Outputs: $name

💡 Hint

In PowerShell, variables must start with $.

The variable 'name' is assigned without $, so PowerShell treats it as a command or string, causing an error when $name is used.

🚀 Application

advanced

How many variables are created after running this script?

Consider this script:

$a = 5
$b = $a
$c = $b + 10

How many variables exist after running it?

PowerShell

$a = 5
$b = $a
$c = $b + 10

A 1

B 0

C 2

D 3

💡 Hint

Each line creates or assigns a variable starting with $.

Variables $a, $b, and $c are all created and assigned values, so there are 3 variables.

🧠 Conceptual

expert

Which option best describes variable naming rules in PowerShell?

Choose the correct statement about variable names in PowerShell.

A Variable names must start with $ and can include letters, numbers, and underscores; they are case-insensitive.

B Variable names must start with $ and only contain letters; numbers are not allowed.

C Variable names can start with any character and are case-sensitive.

D Variable names must start with a letter or underscore and are case-insensitive.

💡 Hint

Remember that $ is part of the variable name syntax in PowerShell.

In PowerShell, variables start with $, can include letters, numbers, and underscores, and are case-insensitive.

Practice

1. What does the $ symbol do in PowerShell when placed before a word like $name?

easy

A. It prints the word 'name' to the screen.

B. It creates a variable named 'name' to store data.

C. It comments out the line.

D. It runs a command called 'name'.

Solution

1. Step 1: Understand the role of $ in PowerShell

   The $ symbol is used to declare or access variables in PowerShell.

2. Step 2: Identify what $name means

   $name means a variable named 'name' that can hold data like text or numbers.

3. Final Answer:

   It creates a variable named 'name' to store data. -> Option B

4. Quick Check:

   $ before word = variable creation [OK]

Hint: Remember: $ always starts a variable name [OK]

Common Mistakes:

• Thinking $ runs commands
• Confusing $ with comments
• Assuming $ prints text directly

2. Which of the following is the correct way to create a variable named age with the value 30 in PowerShell?

easy

A. $age = 30

B. set age = 30

C. age = 30

D. var $age = 30

Solution

1. Step 1: Recall PowerShell variable syntax

   Variables start with $ and assignment uses =.

2. Step 2: Check each option

   $age = 30 uses $age = 30, which is correct syntax for variable creation and assignment.

3. Final Answer:

   $age = 30 -> Option A

4. Quick Check:

   Variable = $name = value [OK]

Hint: Always start variable names with $ in PowerShell [OK]

Common Mistakes:

• Omitting the $ before variable name
• Using 'set' keyword which is not PowerShell syntax
• Adding 'var' keyword which is not used in PowerShell

3. What will be the output of this PowerShell code?

$greeting = "Hello"
$name = "Sam"
Write-Output "$greeting, $name!"

medium

A. Error: Variable not defined

B. $greeting, $name!

C. Hello $name!

D. Hello, Sam!

Solution

1. Step 1: Understand variable assignment

   $greeting is assigned "Hello" and $name is assigned "Sam".

2. Step 2: Understand string interpolation in double quotes

   Inside double quotes, variables like $greeting and $name are replaced by their values.

3. Final Answer:

   Hello, Sam! -> Option D

4. Quick Check:

   Variables inside "" show their values [OK]

Hint: Use double quotes to insert variables inside strings [OK]

Common Mistakes:

• Using single quotes which do not expand variables
• Expecting variable names to print literally
• Forgetting to assign variables before use

4. Identify the error in this PowerShell script:

$number = 10
$number = $number + 5
Write-Output number

medium

A. Cannot add numbers in PowerShell

B. Variable $number not declared

C. Missing $ before 'number' in Write-Output

D. Write-Output cannot print variables

Solution

1. Step 1: Check variable usage in Write-Output

   The script tries to print 'number' without $, so it prints the word literally.

2. Step 2: Correct usage of variable in output

   To print the variable value, it should be Write-Output $number.

3. Final Answer:

   Missing $ before 'number' in Write-Output -> Option C

4. Quick Check:

   Variables need $ to be recognized [OK]

Hint: Always use $ before variable names when printing [OK]

Common Mistakes:

• Forgetting $ before variable in output
• Thinking variables need declaration keyword
• Assuming Write-Output can't print variables

5. You want to create a variable $fullName by combining two variables $firstName and $lastName with a space in between. Which code correctly does this in PowerShell?

hard

A. $fullName = $firstName + " " + $lastName

B. $fullName = '$firstName $lastName'

C. $fullName = $firstName $lastName

D. $fullName = "$firstName$lastName"

Solution

1. Step 1: Understand string concatenation in PowerShell

   Use + to join strings and include a space as " ".

2. Step 2: Analyze each option

   $fullName = $firstName + " " + $lastName correctly adds $firstName, a space, and $lastName to form full name.

3. Final Answer:

   $fullName = $firstName + " " + $lastName -> Option A

4. Quick Check:

   Use + and " " to join variables with space [OK]

Hint: Use + and " " to join variables with space [OK]

Common Mistakes:

• Using single quotes which do not expand variables
• Missing operator between variables
• Concatenating without space when needed