? PHP Logical Operators

? Quick Overview

Logical operators in PHP are used to combine multiple conditions. They evaluate expressions and return true or false depending on the applied logic.

? Key Concepts

• && / and → True if both conditions are true
• || / or → True if at least one condition is true
• ! → Reverses the condition result
• xor → True if only one condition is true

? Syntax & Theory

Logical operators are commonly used in conditional statements such as if, while, and for to control program flow based on multiple conditions.

? Code Examples

// Demonstrating all PHP logical operators
<?php
$age = 20;
$citizen = true;

if ($age >= 18 && $citizen) {
echo "Eligible to vote.";
}

$marks = 40;
if ($marks < 50 || $marks > 90) {
echo "Either low marks or excellent!";
}

$loggedIn = false;
if (!$loggedIn) {
echo "Please log in to continue.";
}

$a = true;
$b = false;
if ($a xor $b) {
echo "Only one is true.";
}
?>

? Live Output / Explanation

The output depends on variable values. Each condition is evaluated using logical rules, and only matching blocks execute.

? Interactive Example

Change variable values like $age or $loggedIn to instantly observe how logical operators alter the execution path.

? Use Cases

• User authentication systems
• Form validation
• Access control and permissions
• Decision-based workflows