Built-in string functions in SASS - Practice Problems & Coding Challenges

Challenge - 5 Problems

📝 Syntax

intermediate

What is the output of this Sass code using string functions?

Consider the following Sass code snippet. What will be the value of $result after compilation?

SASS

$text: "Hello World";
$result: str-insert($text, "-", 6);

A "Hello- World"

B "Hello World-"

C "-Hello World"

D "Hello World"

💡 Hint

The str-insert function inserts a string at a specific index.

The str-insert function inserts the second string argument into the first string at the given index. Index 6 is right after 'Hello', so the dash is inserted there.

🧠 Conceptual

intermediate

Which Sass function returns the length of a string?

You want to find out how many characters are in a string variable in Sass. Which function should you use?

A str-length()

B length()

C string-length()

D count()

💡 Hint

The function name starts with 'str-' and relates to length.

The correct Sass function to get the number of characters in a string is str-length().

❓ selector

advanced

What error occurs when using str-slice with invalid indexes?

Given the Sass code str-slice("Sass", 5, 10), what happens?

A "s"

B "" (empty string)

C Error: Invalid index

D "Sass"

💡 Hint

If the start index is beyond the string length, what does str-slice return?

If the start index is greater than the string length, str-slice returns an empty string instead of an error.

❓ rendering

advanced

What is the output color of this Sass code using string functions?

This Sass code uses string functions to create a color variable. What color will be rendered in the browser?

SASS

$hex: "#1a2b3c";
$color: unquote($hex);
body { background-color: $color; }

A Background color is #1a2b3c (bright red)

B Compilation error due to unquote usage

C Background color is transparent

D Background color is #1a2b3c (a dark blue-gray)

💡 Hint

The unquote function removes quotes so the color is valid CSS.

The variable $color becomes the color code #1a2b3c without quotes, so the background color is a dark blue-gray shade.

❓ accessibility

expert

How can you use Sass string functions to improve accessibility in CSS content?

You want to add dynamic content with a screen reader label using Sass string functions. Which approach correctly combines strings for accessibility?

SASS

$label: "Close button";
$aria: "aria-label='" + $label + "'";
.button::after { content: $aria; }

A Use unquote: content: unquote("aria-label='" + $label + "'");

B Use str-insert to add quotes: content: str-insert($aria, '"', 1);

C Use interpolation: content: "#{"aria-label='" + $label + "'"}";

D Use str-length to set content length: content: str-length($aria);

💡 Hint

Sass interpolation helps combine strings inside content property correctly.

Using interpolation with #{...} correctly inserts the aria-label string as content, making it accessible for screen readers.

Practice

1. Which Sass built-in string function returns the length of a string?
length("hello")

easy

A. Returns the string in uppercase

B. Returns the number of characters in the string

C. Returns the string reversed

D. Returns the first character of the string

Solution

1. Step 1: Understand the length() function

   The length() function in Sass returns how many characters are in a string.

2. Step 2: Apply to the example string

   For the string "hello", the length is 5 characters.

3. Final Answer:

   Returns the number of characters in the string -> Option B

4. Quick Check:

   length("hello") = 5 [OK]

Hint: Remember length() counts characters in a string [OK]

Common Mistakes:

• Confusing length() with uppercase conversion
• Thinking length() returns the first character
• Mixing length() with reverse functions

2. Which of the following is the correct syntax to convert a string to uppercase in Sass?

easy

A. uppercase("text")

B. to-upper-case("text")

C. toUpperCase("text")

D. to-upper("text")

Solution

1. Step 1: Recall Sass string uppercase function

   The correct Sass function to convert a string to uppercase is uppercase().

2. Step 2: Check syntax correctness

   The function is called as uppercase("text"), which matches uppercase("text").

3. Final Answer:

   uppercase("text") -> Option A

4. Quick Check:

   uppercase("text") converts to "TEXT" [OK]

Hint: Use uppercase() exactly as shown for capital letters [OK]

Common Mistakes:

• Using camelCase like toUpperCase() which is not Sass syntax
• Adding dashes incorrectly in function names
• Confusing with CSS text-transform property

3. What is the output of this Sass code?

$str: "Sass";
$result: str-insert($str, "3", 3);

What is the value of $result?

medium

A. "Sass3"

B. "Sas3s"

C. "S3ass"

D. "Sa3ss"

Solution

1. Step 1: Understand str-insert() function

   This function inserts a string into another string at a given index (1-based).

2. Step 2: Apply insertion at position 3

   Original string is "Sass". Insert "3" at position 3 means after the second character: "Sa" + "3" + "ss" = "Sa3ss".

3. Final Answer:

   "Sa3ss" -> Option D

4. Quick Check:

   str-insert("Sass", "3", 3) = "Sa3ss" [OK]

Hint: Remember str-insert uses 1-based index for insertion [OK]

Common Mistakes:

• Using 0-based index instead of 1-based
• Inserting at wrong position
• Confusing str-insert with str-slice

4. Identify the error in this Sass code:

$text: "Hello";
$new-text: str-slice($text, 2, 1);

medium

A. Start index is greater than end index, causing empty string

B. str-slice requires three arguments, missing one

C. Variable names must start with uppercase letters

D. Strings cannot be sliced in Sass

Solution

1. Step 1: Check str-slice() parameters

   The function takes a string, a start index, and an optional end index. Here start=2, end=1.

2. Step 2: Analyze index order

   Since start index (2) is greater than end index (1), the slice returns an empty string, which is likely unintended.

3. Final Answer:

   Start index is greater than end index, causing empty string -> Option A

4. Quick Check:

   str-slice("Hello", 2, 1) = "" (empty) [OK]

Hint: Ensure start index ≤ end index in str-slice() [OK]

Common Mistakes:

• Assuming str-slice needs three arguments always
• Thinking variable names must be uppercase
• Believing strings can't be sliced in Sass

5. You want to create a Sass function that returns the first three characters of a string in uppercase. Which code correctly achieves this?

hard

A. @function first-three-uppercase($str) { @return str-insert(uppercase($str), 3, 1); }

B. @function first-three-uppercase($str) { @return uppercase(str-slice($str, 1)); }

C. @function first-three-uppercase($str) { @return str-slice(uppercase($str), 1, 3); }

D. @function first-three-uppercase($str) { @return uppercase(str-insert($str, 3, 1)); }

Solution

1. Step 1: Understand the goal

   We want the first three characters of the string in uppercase: uppercase first, then slice precisely.

2. Step 2: Analyze each option

   @function first-three-uppercase($str) { @return str-slice(uppercase($str), 1, 3); } uppercases whole string, then slices first 3 characters -- correct.
   @function first-three-uppercase($str) { @return uppercase(str-slice($str, 1)); } str-slice from 1 to end (no end index), uppercases entire string -- incorrect, too many chars.
   @function first-three-uppercase($str) { @return str-insert(uppercase($str), 3, 1); } uses str-insert incorrectly and passes number 3 as insert string -- error.
   @function first-three-uppercase($str) { @return uppercase(str-insert($str, 3, 1)); } similar str-insert misuse -- incorrect.

3. Final Answer:

   @function first-three-uppercase($str) { @return str-slice(uppercase($str), 1, 3); } -> Option C

4. Quick Check:

   str-slice(uppercase($str), 1, 3) returns first 3 uppercase chars [OK]

Hint: Uppercase full string first, then slice first 3 chars [OK]

Common Mistakes:

• Forgetting end index in str-slice causing full string slice
• Using str-insert instead of str-slice
• Passing numbers as insert strings causing type error