PHP switch Statement Explained with Examples

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Learn how to use the switch statement in PHP to simplify complex conditional logic. Includes syntax, code examples, and use cases for beginners and developers.

switch statement

The PHP switch statement is a control structure that allows you to execute different blocks of code based on the value of a variable or expression. It’s a cleaner alternative to multiple if-else statements when dealing with numerous conditions. (Codecademy)

Syntax:

switch ($variable) {
    case 'value1':
        // Code to execute if $variable == 'value1'
        break;
    case 'value2':
        // Code to execute if $variable == 'value2'
        break;
    default:
        // Code to execute if $variable doesn't match any case
}

Key points:

Evaluation: The expression inside the switch is evaluated once.
Case Matching: Each case is compared to the switch expression using loose comparison (==).
Break Statement: The break keyword prevents the code from running into the next case. Omitting break can lead to unintended fall-through behavior.
Default Case: The default case is executed if no matching case is found. It’s good practice to include it to handle unexpected values.(W3Schools.com, DEV Community, Stack Overflow)

Example:

$day = 'Monday';

switch ($day) {
    case 'Monday':
        echo "Start of the work week.";
        break;
    case 'Friday':
        echo "End of the work week.";
        break;
    default:
        echo "Midweek days.";
}

In this example, if $day is ‘Monday’, it will output “Start of the work week.” If it’s ‘Friday’, it will output “End of the work week.” For any other value, it will output “Midweek days.”(Wikipedia)

Best Practices:

Use break Statements: Always include break statements to prevent fall-through unless intentionally desired.
Default Case: Include a default case to handle unexpected values.
Avoid Complex Expressions: Keep case expressions simple to maintain readability.
Consistent Syntax: Stick to a consistent syntax style (either colons or semicolons) for clarity.(TutorialsPoint, Wikipedia)

The statement list for a case can also be empty, which simply passes control into the statement list for the next case.

Example #2 switch with empty case example

<?php
switch ($i) {
    case 0:
    case 1:
    case 2:
        echo "i is less than 3 but not negative";
        break;
    case 3:
        echo "i is 3";
}
?>

Explanation: To understand how this example works in detail, see Switch-Case Example in PHP: Handling Multiple Cases Together.

A special case is the default case. This case matches anything that wasn’t matched by the other cases. For example:

Example #3 default case

<?php

$i = 1
switch ($i) {
    case 0:
        echo "i equals 0";
        break;
    case 1:
        echo "i equals 1";
        break;
    case 2:
        echo "i equals 2";
        break;
    default:
       echo "i is not equal to 0, 1 or 2";
}
?>

Example #4 switch example

<!DOCTYPE html>
<html lang="en">

<head>
    <title>PHP - Switch</title>
</head>

<body>
    <h1>PHP - Switch</h1>
    <?php
$favcolor = "blue";
echo "<h2>My favorite color is " . $favcolor . "</h2>";
switch ($favcolor) {
    case "red":
        echo "<h2 style='color:" . $favcolor . "'>Your favorite color is red!</h2>";
        break;
    case "blue":
        echo "<h2 style='color:" . $favcolor . "'>Your favorite color is blue!</h2>";
        break;
    case "green":
        echo "<h2 style='color:" . $favcolor . "'>Your favorite color is green!</h2>";
        break;
    default:
        echo "Your favorite color is neither red, blue, nor green!";
}
?>
</body>
</html>