Comparison operators (-eq, -ne, -gt, -lt) in PowerShell - Cheat Sheet & Quick Revision

Recall & Review

beginner

What does the PowerShell operator -eq do?

The -eq operator checks if two values are equal. It returns True if they are the same, otherwise False.

beginner

Explain the use of -ne in PowerShell.

The -ne operator means 'not equal'. It returns True if two values are different, and False if they are the same.

beginner

What is the difference between -gt and -lt in PowerShell?

-gt means 'greater than' and checks if the left value is bigger than the right. -lt means 'less than' and checks if the left value is smaller than the right.

beginner

How would you check if a variable $x is greater than 10 in PowerShell?

Use the operator -gt: $x -gt 10. This returns True if $x is more than 10.

beginner

What will 5 -lt 3 return in PowerShell and why?

It returns False because 5 is not less than 3.

Which operator checks if two values are NOT equal in PowerShell?

A -eq

B -gt

C -ne

D -lt

The -ne operator means 'not equal' and returns True if values differ.

What does 7 -gt 5 return?

A Null

B True

C Error

D False

-gt means 'greater than'. 7 is greater than 5, so it returns True.

If $a = 4 and $b = 4, what does $a -eq $b return?

A True

B False

C Null

D Error

Since both values are equal, -eq returns True.

Which operator would you use to check if a number is less than another?

A -ne

B -gt

C -eq

D -lt

-lt means 'less than' and checks if left value is smaller.

What does 10 -ne 10 return?

A False

B True

C Error

D Null

Since both values are equal, -ne returns False.

Describe how to use PowerShell comparison operators to compare two numbers.

Think about how you compare numbers in daily life: equal, not equal, bigger, smaller.

Give an example of a PowerShell command using -gt and explain what it does.

Imagine checking if your age is greater than 18.

Practice

1. Which PowerShell operator checks if two values are equal?

easy

A. -eq

B. -ne

C. -gt

D. -lt

Solution

1. Step 1: Understand the meaning of each operator

   -eq means equals, -ne means not equals, -gt means greater than, -lt means less than.

2. Step 2: Identify the operator for equality

   The operator that checks if two values are equal is -eq.

3. Final Answer:

   -eq -> Option A

4. Quick Check:

   Equals operator = -eq [OK]

Hint: Remember: eq means equal, ne means not equal [OK]

Common Mistakes:

• Confusing -eq with -ne
• Mixing -gt and -lt
• Using == instead of -eq

2. Which of the following is the correct syntax to check if variable $a is greater than 10 in PowerShell?

easy

A. if ($a -gt 10) { }

B. if ($a > 10) { }

C. if ($a -lt 10) { }

D. if ($a -eq 10) { }

Solution

1. Step 1: Recall PowerShell comparison syntax

   PowerShell uses -gt for greater than, not > like some other languages.

2. Step 2: Match the correct operator

   The correct syntax to check if $a is greater than 10 is if ($a -gt 10) { }.

3. Final Answer:

   if ($a -gt 10) { } -> Option A

4. Quick Check:

   Greater than operator = -gt [OK]

Hint: Use -gt for greater than, not > in PowerShell [OK]

Common Mistakes:

• Using > instead of -gt
• Confusing -lt with -gt
• Missing parentheses in if statement

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

$x = 5
if ($x -ne 5) { 'No' } else { 'Yes' }

medium

A. 5

B. No

C. Yes

D. False

Solution

1. Step 1: Evaluate the condition $x -ne 5

   $x is 5, so $x -ne 5 means 5 not equal to 5, which is False.

2. Step 2: Determine which block runs

   Since condition is False, the else block runs, outputting 'Yes'.

3. Final Answer:

   Yes -> Option C

4. Quick Check:

   5 not equal 5 is False, so else runs [OK]

Hint: -ne means not equal; false triggers else block [OK]

Common Mistakes:

• Thinking -ne means equal
• Confusing output with variable value
• Ignoring else block

4. Identify the error in this PowerShell snippet:

$num = 10
if ($num -gt 5) { 'Greater' } elseif ($num -lt 5) { 'Smaller' } else { 'Equal' }

medium

A. Missing closing brace for if block

B. No error, code runs correctly

C. Incorrect use of elseif instead of else if

D. Using -gt instead of > operator

Solution

1. Step 1: Check syntax of if-elseif-else

   PowerShell supports elseif as one word; braces are balanced.

2. Step 2: Verify operators and structure

   -gt and -lt are correct operators; no syntax errors present.

3. Final Answer:

   No error, code runs correctly -> Option B

4. Quick Check:

   elseif is valid in PowerShell [OK]

Hint: PowerShell uses elseif as one word, not else if [OK]

Common Mistakes:

• Thinking elseif is invalid
• Expecting > instead of -gt
• Missing braces confusion

5. You want to write a PowerShell script that prints 'Valid' only if a variable $score is greater than or equal to 70. Which code snippet correctly uses comparison operators to achieve this?

hard

A. if ($score -gt 70) { 'Valid' } else { 'Invalid' }

B. if ($score -lt 70) { 'Valid' } else { 'Invalid' }

C. if ($score -eq 70) { 'Valid' } else { 'Invalid' }

D. if ($score -ge 70) { 'Valid' } else { 'Invalid' }

Solution

1. Step 1: Understand the requirement

   We want to check if $score is greater than or equal to 70.

2. Step 2: Identify the correct operator

   -ge means greater than or equal to, which matches the requirement.

3. Final Answer:

   if ($score -ge 70) { 'Valid' } else { 'Invalid' } -> Option D

4. Quick Check:

   Greater or equal operator = -ge [OK]

Hint: Use -ge for greater or equal comparisons [OK]

Common Mistakes:

• Using -gt excludes 70
• Using -eq only matches exactly 70
• Using -lt reverses logic