PHP program to find the perimeter of rectangle

A rectangle is a closed two-dimensional figure with 4 sides where opposite sides are equal and parallel. The perimeter is the total distance around the rectangle, calculated by adding all four sides. In this tutorial, we'll learn different PHP approaches to calculate rectangle perimeter.

Formula

The formula for calculating rectangle perimeter is

Perimeter = 2 × (Length + Breadth)

Where length is the horizontal distance and breadth is the vertical distance.

Direct Formula Approach

The simplest method uses the direct formula to calculate perimeter

<?php
$length = 10;
$breadth = 5;

// Calculate perimeter using the formula
$perimeter = 2 * ($length + $breadth);

// Output the result
echo "Length: $length units
";
echo "Breadth: $breadth units
";
echo "Perimeter: $perimeter units
";
?>

Length: 10 units
Breadth: 5 units
Perimeter: 30 units

Using Function

Creating a reusable function for perimeter calculation

<?php
// Function to calculate rectangle perimeter
function calculatePerimeter($length, $breadth) {
    return 2 * ($length + $breadth);
}

// Test with different values
$length1 = 15;
$breadth1 = 8;
$perimeter1 = calculatePerimeter($length1, $breadth1);

$length2 = 20;
$breadth2 = 12;
$perimeter2 = calculatePerimeter($length2, $breadth2);

echo "Rectangle 1: Length=$length1, Breadth=$breadth1, Perimeter=$perimeter1
";
echo "Rectangle 2: Length=$length2, Breadth=$breadth2, Perimeter=$perimeter2
";
?>

Rectangle 1: Length=15, Breadth=8, Perimeter=46
Rectangle 2: Length=20, Breadth=12, Perimeter=64

With Input Validation

Adding validation to handle edge cases

<?php
function calculatePerimeterSafe($length, $breadth) {
    // Validate inputs
    if ($length <= 0 || $breadth <= 0) {
        return "Error: Length and breadth must be positive numbers";
    }
    
    return 2 * ($length + $breadth);
}

// Test cases
$testCases = [
    [10, 5],
    [0, 8],
    [15, 10],
    [-5, 3]
];

foreach ($testCases as $case) {
    $result = calculatePerimeterSafe($case[0], $case[1]);
    echo "Length: {$case[0]}, Breadth: {$case[1]} ? $result
";
}
?>

Length: 10, Breadth: 5 ? 30
Length: 0, Breadth: 8 ? Error: Length and breadth must be positive numbers
Length: 15, Breadth: 10 ? 50
Length: -5, Breadth: 3 ? Error: Length and breadth must be positive numbers

Comparison

Conclusion

Rectangle perimeter calculation in PHP is straightforward using the formula 2 × (length + breadth). Use functions for reusability and always validate inputs in production applications to handle edge cases properly.