Switch statement execution in PHP - Practice Problems & Coding Challenges

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of switch with fall-through

What is the output of this PHP code?

PHP

<?php
$val = 2;
switch ($val) {
    case 1:
        echo "One ";
    case 2:
        echo "Two ";
    case 3:
        echo "Three ";
        break;
    default:
        echo "Default ";
}
?>

A One Two Three

B Two Three

C Two

D Default

💡 Hint

Remember that without break, cases fall through to the next.

The switch starts at case 2, prints 'Two ', then falls through to case 3 and prints 'Three ', then breaks.

❓ Predict Output

intermediate

Switch with strict type comparison

What will this PHP code output?

PHP

<?php
$value = '5';
switch ($value) {
    case 5:
        echo "Number 5";
        break;
    case '5':
        echo "String 5";
        break;
    default:
        echo "No match";
}
?>

A Number 5

B String 5

C No match

D Error

💡 Hint

PHP switch uses loose comparison (==), not strict (===).

The string '5' loosely equals the integer 5, so case 5 matches first and prints 'Number 5'.

🔧 Debug

advanced

Identify the error in switch syntax

Which option contains a syntax error in the switch statement?

A

<?php
switch ($x) {
    case 1:
        echo "One";
        break;
    default
        echo "Default";
}
?>

B

<?php
switch ($x) {
    case 1:
        echo "One";
        break;
    default:
        echo "Default";
}
?>

C

<?php
switch ($x) {
    case 1:
        echo "One";
        break;
    case 2:
        echo "Two";
        break;
}
?>

D

<?php
switch ($x) {
    case 1:
        echo "One";
        break;
    case 2:
        echo "Two";
        break;
    default:
        echo "Default";
}
?>

💡 Hint

Check the syntax for the default case.

Option A misses the colon ':' after 'default', causing a syntax error.

❓ Predict Output

advanced

Switch with multiple cases and no breaks

What is the output of this PHP code?

PHP

<?php
$val = 1;
switch ($val) {
    case 0:
    case 1:
    case 2:
        echo "Low ";
    case 3:
        echo "Mid ";
        break;
    default:
        echo "High ";
}
?>

A Mid

B Low

C Low Mid

D High

💡 Hint

Cases 0,1,2 share the same block without breaks.

Value 1 matches case 1, prints 'Low ', then falls through to case 3 and prints 'Mid ', then breaks.

🧠 Conceptual

expert

Behavior of switch with non-scalar expression

What happens when you use an array as the switch expression in PHP like this?

PHP

<?php
$arr = [1, 2];
switch ($arr) {
    case [1, 2]:
        echo "Match";
        break;
    default:
        echo "No match";
}
?>

A Outputs 'Match' because arrays are compared by value.

B Outputs 'No match' because switch cannot compare arrays.

C Causes a fatal error due to invalid switch expression.

D Raises a warning and outputs 'No match'.

💡 Hint

PHP switch uses loose comparison but arrays in switch cause warnings.

Using arrays in switch causes a warning: 'Warning: Switch statement with non-scalar expression', then default runs printing 'No match'.