Switch statement execution in PHP - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to start a switch statement with the variable $color.

PHP

<?php
$color = 'red';
switch([1]) {
    case 'red':
        echo 'Stop';
        break;
    default:
        echo 'Go';
}
?>

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

Acolor

B$colour

C$color

Dred

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting the dollar sign in front of the variable.

Using a misspelled variable name.

The switch statement must use the variable $color to check its value.

2fill in blank

medium

Complete the code to print 'Go' when the color is not 'red' or 'yellow'.

PHP

<?php
$color = 'green';
switch ($color) {
    case 'red':
        echo 'Stop';
        break;
    case 'yellow':
        echo 'Caution';
        break;
    [1]:
        echo 'Go';
}
?>

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

Aelse

Bdefault

Ccase 'green'

Dbreak

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'else' instead of 'default' in switch.

Forgetting to add a colon after the case or default.

The default case runs when no other case matches.

3fill in blank

hard

Fix the error in the switch statement to correctly break after the 'yellow' case.

PHP

<?php
$color = 'yellow';
switch ($color) {
    case 'red':
        echo 'Stop';
        break;
    case 'yellow':
        echo 'Caution';
        [1]
    default:
        echo 'Go';
}
?>

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

Abreak

Bexit

Ccontinue

Dreturn

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'continue' which is for loops, not switch.

Forgetting to add any statement to stop fall-through.

The break statement stops the switch from continuing to the next cases.

4fill in blank

hard

Fill both blanks to create a switch that prints 'Weekend' for 'Saturday' and 'Sunday', and 'Weekday' otherwise.

PHP

<?php
$day = 'Sunday';
switch([1]) {
    case 'Saturday':
    case [2]:
        echo 'Weekend';
        break;
    default:
        echo 'Weekday';
}
?>

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

A$day

B'Sunday'

Attempts:

3 left

💡 Hint

Common Mistakes

Using the variable name without the dollar sign.

Using the variable instead of the string for the second case.

The switch uses $day to check the day. The second case must be the string 'Sunday' to group weekend days.

5fill in blank

hard

Fill all three blanks to create a switch that prints 'Low', 'Medium', or 'High' based on the $level variable.

PHP

<?php
$level = 2;
switch([1]) {
    case 1:
        echo [2];
        break;
    case 2:
        echo [3];
        break;
    default:
        echo 'High';
}
?>

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

A$level

B'Low'

C'Medium'

Attempts:

3 left

💡 Hint

Common Mistakes

Not quoting the strings in echo.

Using the wrong variable name in the switch.

The switch checks the variable $level. For case 1, it prints 'Low'. For case 2, it prints 'Medium'. Otherwise, it prints 'High'.

Practice

1. What does a switch statement do in PHP?

easy

A. It chooses which code to run based on a value.

B. It repeats code multiple times.

C. It defines a function.

D. It creates a new variable.

Solution

1. Step 1: Understand the purpose of switch

   A switch statement compares a value to multiple cases to decide which code block to run.

2. Step 2: Compare with other options

   Repeating code is done by loops, functions define reusable code, and variables store data, so these are not correct.

3. Final Answer:

   It chooses which code to run based on a value. -> Option A

4. Quick Check:

   Switch selects code by value = A [OK]

Hint: Switch picks code by matching value quickly [OK]

Common Mistakes:

• Confusing switch with loops
• Thinking switch defines functions
• Believing switch creates variables

2. Which of the following is the correct syntax to start a switch statement in PHP?

easy

A. switch [variable] {

B. switch variable {

C. switch (variable) {

D. switch variable() {

Solution

1. Step 1: Recall switch syntax

   In PHP, switch requires parentheses around the variable: switch (variable) {

2. Step 2: Check other options

   Options without parentheses or with brackets or parentheses after variable name are invalid syntax.

3. Final Answer:

   switch (variable) { -> Option C

4. Quick Check:

   Switch uses parentheses around variable [OK]

Hint: Switch always uses parentheses around the variable [OK]

Common Mistakes:

• Omitting parentheses
• Using square brackets instead of parentheses
• Adding parentheses after variable name

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

 $color = 'red';
 switch ($color) {
   case 'blue':
     echo 'Blue color';
     break;
   case 'red':
     echo 'Red color';
     break;
   default:
     echo 'No color';
 }

medium

A. Blue color

B. Syntax error

C. No color

D. Red color

Solution

1. Step 1: Check the value of $color

   $color is set to 'red'.

2. Step 2: Match cases in switch

   The switch checks 'blue' first (no match), then 'red' (match), so it runs echo 'Red color' and breaks.

3. Final Answer:

   Red color -> Option D

4. Quick Check:

   Value 'red' matches case 'red' [OK]

Hint: Match value to case, break stops further checks [OK]

Common Mistakes:

• Forgetting break causes fall-through
• Assuming default runs even if case matches
• Mixing case values

4. Identify the error in this PHP switch code:

 $day = 3;
 switch ($day) {
   case 1:
     echo 'Monday';
   case 2:
     echo 'Tuesday';
     break;
   default:
     echo 'Other day';
 }

medium

A. Missing break after case 1 causes fall-through.

B. Switch statement syntax is incorrect.

C. Variable $day is not defined.

D. Default case should be first.

Solution

1. Step 1: Check breaks in cases

   Case 1 has no break, so if matched, it falls through to case 2.

2. Step 2: Understand effect of missing break

   Missing break causes code for case 2 to run even if case 1 matches, which is usually unintended.

3. Final Answer:

   Missing break after case 1 causes fall-through. -> Option A

4. Quick Check:

   Break missing after case 1 causes fall-through [OK]

Hint: Always add break after each case to avoid fall-through [OK]

Common Mistakes:

• Ignoring missing break causes multiple cases to run
• Thinking default must be first
• Assuming variable is undefined

5. Given this PHP code, what will be the output?

 $score = 85;
 switch (true) {
   case ($score >= 90):
     echo 'Grade A';
     break;
   case ($score >= 80):
     echo 'Grade B';
     break;
   case ($score >= 70):
     echo 'Grade C';
     break;
   default:
     echo 'Fail';
 }

hard

A. Grade A

B. Grade B

C. Grade C

D. Fail

Solution

1. Step 1: Understand switch(true) usage

   The switch compares true to each case condition result.

2. Step 2: Evaluate each case condition

   $score is 85, so ($score >= 90) is false, ($score >= 80) is true, so it matches case 2 and prints 'Grade B'.

3. Final Answer:

   Grade B -> Option B

4. Quick Check:

   Switch(true) matches first true case = Grade B [OK]

Hint: Use switch(true) to check conditions in order [OK]

Common Mistakes:

• Expecting switch to compare values directly
• Not understanding switch(true) trick
• Missing break causing fall-through