Range operator (..) in PowerShell - Practice Problems & Coding Challenges

Challenge - 5 Problems

💻 Command Output

intermediate

What is the output of this PowerShell range operator?

Consider the following PowerShell command:

$result = 5..8
$result

What will be the output?

PowerShell

$result = 5..8
$result

A 5 6 7 8

B 5..8

C 8 7 6 5

D Error: Invalid range operator usage

💡 Hint

The range operator creates a sequence of numbers from the first to the second number.

The range operator (..) in PowerShell generates an array of integers starting from the left number up to the right number inclusive. So 5..8 produces 5, 6, 7, 8.

💻 Command Output

intermediate

What does this PowerShell code output?

Look at this code snippet:

$numbers = 10..7
$numbers

What will be the output?

PowerShell

$numbers = 10..7
$numbers

A 10 9 8 7

B 7 8 9 10

C 10 7

D Empty array

💡 Hint

The range operator counts down if the first number is greater than the second.

PowerShell's range operator creates an ascending sequence only if the first number is less than or equal to the second. If the first number is greater, it produces an empty array. So 10..7 produces an empty array.

📝 Syntax

advanced

Which option correctly uses the range operator to create an array from 3 to 6?

Select the PowerShell code that correctly creates an array containing numbers 3, 4, 5, and 6.

A $arr = 3..6..1

B $arr = 3..6

C $arr = 3-6

D $arr = 3...6

💡 Hint

The range operator uses two dots between numbers.

The correct syntax for the range operator is two dots (..). Option B uses this correctly. Option B has three dots which is invalid syntax. Option B uses a dash which is subtraction, not range. Option B uses extra dots which is invalid.

🚀 Application

advanced

How many elements are in the array created by this range?

Given this PowerShell code:

$array = 15..10

How many elements does $array contain?

A 4

B 5

C 0

D 6

💡 Hint

Count all numbers from 15 down to 10 inclusive.

PowerShell's range operator only creates ascending sequences. Since 15 is greater than 10, the range 15..10 produces an empty array with 0 elements.

🧠 Conceptual

expert

What error does this PowerShell code produce?

Analyze this code:

$result = 5..'8'

What happens when you run it?

A Error: Cannot convert value '8' to type 'System.Int32'

B Outputs: 5 '8'

C Outputs: 5 6 7 8

D Empty array

💡 Hint

The range operator requires both ends to be integers.

PowerShell cannot create a range when one end is a string that cannot be converted to an integer automatically. This causes a conversion error.

Practice

1. What does the PowerShell range operator 1..5 produce?

easy

A. An empty list

B. A list of numbers from 5 to 1 inclusive

C. A syntax error

D. A list of numbers from 1 to 5 inclusive

Solution

1. Step 1: Understand the range operator syntax

   The range operator .. creates a sequence of numbers from the first number to the second number.

2. Step 2: Apply the operator to 1..5

   It creates a list starting at 1 and ending at 5, including both ends.

3. Final Answer:

   A list of numbers from 1 to 5 inclusive -> Option D

4. Quick Check:

   Range 1..5 = 1,2,3,4,5 [OK]

Hint: Range operator lists numbers from start to end inclusive [OK]

Common Mistakes:

• Thinking it counts down by default
• Expecting exclusive end value
• Confusing syntax with other operators

2. Which of the following is the correct syntax to create a descending range from 5 to 1 in PowerShell?

easy

A. 5-1

B. 1..5

C. 5..1

D. range(5,1)

Solution

1. Step 1: Identify how to create descending ranges

   PowerShell range operator supports descending ranges by placing the higher number first.

2. Step 2: Check the options

   5..1 uses 5..1 which creates a descending list from 5 down to 1.

3. Final Answer:

   5..1 -> Option C

4. Quick Check:

   Descending range = 5..1 [OK]

Hint: Put larger number first for descending range [OK]

Common Mistakes:

• Using 1..5 for descending range
• Using invalid syntax like 5-1
• Using non-PowerShell functions like range()

3. What is the output of this PowerShell command?

1..3 | ForEach-Object { $_ * 2 }

medium

A. 2 4 6

B. 1 2 3

C. 3 6 9

D. Error: Invalid operation

Solution

1. Step 1: Understand the range and pipeline

   The range operator 1..3 produces 1, 2, 3 which are piped one by one.

2. Step 2: Multiply each number by 2

   Each number is multiplied by 2: 1*2=2, 2*2=4, 3*2=6.

3. Final Answer:

   2 4 6 -> Option A

4. Quick Check:

   1..3 * 2 = 2 4 6 [OK]

Hint: Range pipes each number; multiply inside loop [OK]

Common Mistakes:

• Expecting original numbers without multiplication
• Confusing multiplication with addition
• Thinking it produces a syntax error

4. You wrote this code but it throws an error:

5..1..1

What is the problem?

medium

A. Range operator does not support three dots

B. Range operator requires spaces between dots

C. Range operator only works with ascending numbers

D. Range operator needs parentheses around numbers

Solution

1. Step 1: Analyze the syntax used

   The code uses three dots .. twice in a row, making ..1..1 which is invalid.

2. Step 2: Understand range operator limitations

   The range operator only supports two dots .. between two numbers, not three dots or step values.

3. Final Answer:

   Range operator does not support three dots -> Option A

4. Quick Check:

   Only two dots allowed in range operator [OK]

Hint: Range operator uses exactly two dots (..), no more [OK]

Common Mistakes:

• Trying to add step value with extra dots
• Adding spaces between dots
• Assuming parentheses fix syntax

5. You want to create a list of even numbers from 2 to 10 using the range operator and filtering. Which script correctly does this?

hard

A. 2..10 | ForEach-Object { $_ * 2 }

B. 2..10 | Where-Object { $_ % 2 -eq 0 }

C. 1..5 | Where-Object { $_ % 2 -eq 0 }

D. 2..10..2

Solution

1. Step 1: Understand the range and filtering

   The range operator 2..10 creates numbers 2 to 10. Filtering with Where-Object { $_ % 2 -eq 0 } keeps only even numbers.

2. Step 2: Check each option

   2..10 | Where-Object { $_ % 2 -eq 0 } correctly filters evens from 2 to 10. 2..10 | ForEach-Object { $_ * 2 } doubles numbers 2 to 10 (wrong). 1..5 | Where-Object { $_ % 2 -eq 0 } filters evens from 1 to 5 (wrong range). 2..10..2 uses invalid syntax (range operator does not support step).

3. Final Answer:

   2..10 | Where-Object { $_ % 2 -eq 0 } -> Option B

4. Quick Check:

   Filter evens from range with Where-Object [OK]

Hint: Use Where-Object to filter even numbers after range [OK]

Common Mistakes:

• Trying to add step in range operator
• Using wrong range limits
• Multiplying instead of filtering