Match expression (PHP 8) - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of a simple match expression

What is the output of the following PHP code using a match expression?

PHP

<?php
$input = 2;
$result = match($input) {
    1 => 'One',
    2 => 'Two',
    3 => 'Three',
    default => 'Other'
};
echo $result;

A Two

B One

C Three

D Other

💡 Hint

Look at the value of $input and which case it matches.

The match expression compares $input to each case. Since $input is 2, it matches the case 2 and returns 'Two'.

❓ Predict Output

intermediate

Match expression with multiple conditions

What will this PHP code output when using a match expression with multiple conditions in one arm?

PHP

<?php
$input = 'b';
$result = match($input) {
    'a', 'b', 'c' => 'Letter in a-c',
    'x', 'y', 'z' => 'Letter in x-z',
    default => 'Other letter'
};
echo $result;

A Letter in x-z

B Other letter

C Letter in a-c

D Syntax error

💡 Hint

Check which group the input letter belongs to.

The input 'b' matches the first arm with multiple conditions 'a', 'b', 'c', so it returns 'Letter in a-c'.

❓ Predict Output

advanced

Match expression with strict type comparison

What is the output of this PHP code using match expression with strict type comparison?

PHP

<?php
$input = '1';
$result = match($input) {
    1 => 'Integer one',
    '1' => 'String one',
    default => 'Other'
};
echo $result;

A Integer one

B TypeError

C Other

D String one

💡 Hint

Match uses strict comparison (===), so type matters.

The input is a string '1', so it matches the case '1' (string) and returns 'String one'. The integer 1 case does not match because types differ.

❓ Predict Output

advanced

Match expression without default arm

What happens when this PHP code runs a match expression without a default arm and no case matches?

PHP

<?php
$input = 5;
$result = match($input) {
    1 => 'One',
    2 => 'Two',
    3 => 'Three'
};
echo $result;

A One

B UnhandledMatchError

C Three

D Two

💡 Hint

What if no case matches and no default is given?

If no case matches and there is no default arm, PHP throws an UnhandledMatchError exception.

🧠 Conceptual

expert

Behavior of match expression with expressions as arms

Consider this PHP code using match expression with expressions as arms. What is the output?

PHP

<?php
$input = 3;
$result = match($input) {
    1 => 1 + 1,
    2 => 2 * 2,
    3 => strlen('abc'),
    default => 0
};
echo $result;

A 3

B 2

C 4

D 0

💡 Hint

Evaluate the expression for the matching case.

The input is 3, so the matching arm is 3 => strlen('abc'). strlen('abc') returns 3, so the output is 3.

Practice

1. What is the main advantage of using a match expression in PHP 8 compared to a switch statement?

easy

A. It returns a value and uses strict comparison.

B. It allows fall-through between cases.

C. It only works with strings.

D. It requires a default case.

Solution

1. Step 1: Understand match vs switch behavior

   Match expressions return a value directly, unlike switch which is a statement.

2. Step 2: Identify comparison type

   Match uses strict comparison (===), while switch uses loose comparison (==).

3. Final Answer:

   It returns a value and uses strict comparison. -> Option A

4. Quick Check:

   Match returns value + strict check [OK]

Hint: Remember: match returns values and checks types strictly [OK]

Common Mistakes:

• Thinking match allows fall-through like switch
• Believing match works only with strings
• Assuming default case is mandatory in match

2. Which of the following is the correct syntax for a simple match expression in PHP 8?

easy

A. match ($value) { 1 => 'one', 2 => 'two', default => 'other' };

B. match $value { 1: 'one', 2: 'two', default: 'other' };

C. match ($value) { 1: 'one', 2: 'two', default => 'other' };

D. match ($value) { 1 => 'one', 2 => 'two', _ => 'other' };

Solution

1. Step 1: Recall match syntax

   Match uses parentheses around the expression and curly braces with arrows (=>) for cases.

2. Step 2: Identify correct default syntax

   Default case uses the keyword default with =>, not _ or colon.

3. Final Answer:

   match ($value) { 1 => 'one', 2 => 'two', default => 'other' }; -> Option A

4. Quick Check:

   Correct syntax uses parentheses, arrows, and default keyword [OK]

Hint: Use parentheses and arrows => with default keyword [OK]

Common Mistakes:

• Using colon : instead of arrow =>
• Omitting parentheses around the match expression
• Using _ instead of default for fallback

3. What will be the output of the following PHP code?

$status = 2;
$message = match($status) {
    1 => 'Pending',
    2 => 'Approved',
    3 => 'Rejected',
    default => 'Unknown'
};
echo $message;

medium

A. Pending

B. Unknown

C. Rejected

D. Approved

Solution

1. Step 1: Identify the value of $status

   $status is set to 2.

2. Step 2: Match $status to cases

   Case 2 matches 'Approved'.

3. Final Answer:

   Approved -> Option D

4. Quick Check:

   Value 2 matches 'Approved' [OK]

Hint: Match returns the value for exact case match [OK]

Common Mistakes:

• Confusing default case with matched case
• Assuming loose comparison might match wrong case
• Forgetting match returns a value, not prints it

4. Identify the error in this PHP 8 match expression code:

$input = 'banana';
$result = match($input) {
    'apple' => 'fruit',
    'carrot' => 'vegetable'
};
echo $result;

medium

A. Match expression cannot use strings as cases.

B. Syntax error due to missing semicolon after match.

C. Missing default case causes UnhandledMatchError.

D. Variable $result is not assigned properly.

Solution

1. Step 1: Check for default case presence

   The match expression lacks a default case for unmatched values.

2. Step 2: Understand consequences

   If input does not match any case, PHP throws UnhandledMatchError.

3. Final Answer:

   Missing default case causes UnhandledMatchError. -> Option C

4. Quick Check:

   Always include default to avoid errors [OK]

Hint: Always add default case to handle unmatched values [OK]

Common Mistakes:

• Assuming default case is optional
• Thinking strings can't be used as match cases
• Confusing syntax errors with runtime errors

5. You want to categorize a number into 'small', 'medium', or 'large' using a PHP 8 match expression. Which code correctly implements this logic for:
- small: 1 or 2
- medium: 3 or 4
- large: any other number

$num = 3;
// Your match expression here

hard

A. match($num) { 1, 2 => 'small', 3, 4 => 'medium', _ => 'large' };

B. match($num) { 1, 2 => 'small', 3, 4 => 'medium', default => 'large' };

C. match $num { 1, 2 => 'small', 3, 4 => 'medium', default => 'large' };

D. match($num) { 1, 2: 'small', 3, 4: 'medium', default => 'large' };

Solution

1. Step 1: Use comma-separated values for multiple cases

   PHP 8 match allows multiple values per case separated by commas.

2. Step 2: Use correct default keyword

   Default fallback must use default keyword, not underscore or other.

3. Final Answer:

   match($num) { 1, 2 => 'small', 3, 4 => 'medium', default => 'large' }; -> Option B

4. Quick Check:

   Multiple values + default keyword = match($num) { 1, 2 => 'small', 3, 4 => 'medium', default => 'large' }; [OK]

Hint: Use commas for multiple cases and default keyword for fallback [OK]

Common Mistakes:

• Using _ instead of default for fallback
• Not separating multiple cases with commas
• Confusing syntax with switch statement