@if conditional logic in SASS - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to apply red color only if $is-error is true.

SASS

$is-error: true;

.error-message {
  @if [1] {
    color: red;
  }
}

Drag options to blanks, or click blank then click option'

A$is-error

B$error

Cis-error

Derror

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the $ sign before the variable name.

Using a variable name that is not defined.

The @if directive checks the condition inside parentheses. Here, $is-error is the correct variable to check.

2fill in blank

medium

Complete the code to set background to green if $status equals 'success'.

SASS

$status: 'success';

.status {
  @if $status [1] 'success' {
    background: green;
  }
}

Drag options to blanks, or click blank then click option'

A===

B=

C==

D!=

Attempts:

3 left

💡 Hint

Common Mistakes

Using = instead of == for comparison.

Using !== or === which are JavaScript operators, not Sass.

In Sass, the equality operator is == to compare values inside @if.

3fill in blank

hard

Fix the error in the code to check if $width is greater than 100px.

SASS

$width: 120px;

.container {
  @if $width [1] 100px {
    width: $width;
  }
}

Drag options to blanks, or click blank then click option'

A=>

B>

C<

D==

Attempts:

3 left

💡 Hint

Common Mistakes

Using => instead of >.

Using == which checks equality, not greater than.

The correct operator for 'greater than' in Sass is >. The => operator is invalid here.

4fill in blank

hard

Fill both blanks to set font-size to 2rem if $large-text is true and $screen-width is at least 600px.

SASS

$large-text: true;
$screen-width: 700px;

.text {
  @if [1] and [2] {
    font-size: 2rem;
  }
}

Drag options to blanks, or click blank then click option'

A$large-text

B$screen-width >= 600px

C$screen-width > 600px

D$large-text == false

Attempts:

3 left

💡 Hint

Common Mistakes

Using > instead of >= which excludes 600px exactly.

Using $large-text == false which is the opposite condition.

The condition checks if $large-text is true and $screen-width is greater or equal to 600px using >=.

5fill in blank

hard

Fill all three blanks to create a conditional that sets margin to 1rem if $is-mobile is true, $orientation is 'portrait', and $width is less than 500px.

SASS

$is-mobile: true;
$orientation: 'portrait';
$width: 480px;

.container {
  @if [1] and [2] and [3] {
    margin: 1rem;
  }
}

Drag options to blanks, or click blank then click option'

A$is-mobile

B$orientation == 'portrait'

C$width < 500px

D$width > 500px

Attempts:

3 left

💡 Hint

Common Mistakes

Using > instead of < for $width comparison.

Forgetting to compare $orientation to 'portrait'.

All three conditions must be true: $is-mobile is true, $orientation equals 'portrait', and $width is less than 500px.

Practice

1. What does the @if directive do in Sass?

easy

A. It defines a variable.

B. It loops through a list of items.

C. It imports other Sass files.

D. It applies styles only if a condition is true.

Solution

1. Step 1: Understand the purpose of @if

   The @if directive checks a condition and applies styles only when that condition is true.

2. Step 2: Compare with other options

   Looping is done with @for or @each, importing with @import, and variables are defined with $.

3. Final Answer:

   It applies styles only if a condition is true. -> Option D

4. Quick Check:

   @if = conditional style application [OK]

Hint: Remember: @if controls styles by conditions [OK]

Common Mistakes:

• Confusing @if with loops or imports
• Thinking @if defines variables
• Assuming @if always runs styles

2. Which of the following is the correct syntax for using @if in Sass?

easy

A. @if $color == red { color: red; }

B. @if ($color = red) { color: red; }

C. @if $color === red { color: red; }

D. @if $color => red { color: red; }

Solution

1. Step 1: Check the correct comparison operator

   Sass uses == to compare values in @if conditions, not =, ===, or =>.

2. Step 2: Verify syntax structure

   The correct syntax is @if $variable == value { ... } without parentheses around the condition.

3. Final Answer:

   @if $color == red { color: red; } -> Option A

4. Quick Check:

   Use == for comparison in @if [OK]

Hint: Use double equals (==) for conditions in @if [OK]

Common Mistakes:

• Using single equals (=) instead of double (==)
• Adding parentheses around condition
• Using JavaScript style === or =>

3. What will be the output CSS of this Sass code?

$theme: dark;

body {
  @if $theme == light {
    background: white;
    color: black;
  } @else if $theme == dark {
    background: black;
    color: white;
  } @else {
    background: gray;
    color: black;
  }
}

medium

A. body { background: black; color: white; }

B. body { background: white; color: black; }

C. body { background: gray; color: black; }

D. No output due to syntax error

Solution

1. Step 1: Check the value of $theme

   The variable $theme is set to dark.

2. Step 2: Evaluate the @if conditions

   The first condition $theme == light is false, so it skips to @else if $theme == dark, which is true. So it applies background: black; and color: white;.

3. Final Answer:

   body { background: black; color: white; } -> Option A

4. Quick Check:

   $theme = dark triggers @else if dark block [OK]

Hint: Match variable value to @if conditions carefully [OK]

Common Mistakes:

• Choosing first @if block without checking variable
• Ignoring @else if and @else blocks
• Assuming syntax error without checking carefully

4. Identify the error in this Sass code:

$size: 10px;

.box {
  @if $size > 5 {
    width: $size;
  } @else if $size < 5 {
    width: 5px;
  }
}

medium

A. Missing @else block for equal size case.

B. Units like px cannot be compared directly in @if.

C. Comparison operators like > and < are not allowed in @if.

D. Variable $size should be declared inside the block.

Solution

1. Step 1: Understand unit comparison in Sass

   Sass does not allow direct comparison of values with units like 10px > 5 in @if conditions.

2. Step 2: Check other options

   Comparison operators are allowed, @else block is optional, and variables can be declared outside blocks.

3. Final Answer:

   Units like px cannot be compared directly in @if. -> Option B

4. Quick Check:

   Cannot compare px units directly in @if [OK]

Hint: Avoid comparing units directly; use numbers or functions [OK]

Common Mistakes:

• Thinking > and < are invalid operators
• Assuming @else is mandatory
• Declaring variables only inside blocks

5. You want to set a button's background color based on a variable $status that can be 'success', 'warning', or 'error'. Which Sass code correctly uses @if conditional logic to apply green for success, yellow for warning, and red for error, with a default gray if none match?

hard

A. @if $status = success {
background: green;
} @else if $status == warning {
background: yellow;
} @else if $status == error {
background: red;
} @else {
background: gray;
}

B. @if $status = 'success' {
background: green;
} @else if $status = 'warning' {
background: yellow;
} @else if $status = 'error' {
background: red;
} @else {
background: gray;
}

C. @if $status == 'success' {
background: green;
} @else if $status == 'warning' {
background: yellow;
} @else if $status == 'error' {
background: red;
} @else {
background: gray;
}

D. @if $status === 'success' {
background: green;
} @else if $status === 'warning' {
background: yellow;
} @else if $status === 'error' {
background: red;
} @else {
background: gray;
}

Solution

1. Step 1: Check string comparison syntax

   In Sass, string values must be quoted and compared with ==, not = or ===.

2. Step 2: Verify the use of quotes around strings

   Options A and B miss quotes or use wrong operators; @if $status === 'success' { background: green; } @else if $status === 'warning' { background: yellow; } @else if $status === 'error' { background: red; } @else { background: gray; } uses === which is invalid in Sass.

3. Final Answer:

   @if $status == 'success' { background: green; } @else if $status == 'warning' { background: yellow; } @else if $status == 'error' { background: red; } @else { background: gray; } -> Option C

4. Quick Check:

   Use == and quotes for string comparison in @if [OK]

Hint: Compare strings with == and quotes in @if [OK]

Common Mistakes:

• Using single equals (=) instead of double (==)
• Omitting quotes around strings
• Using JavaScript style === operator