lab3_task1.php

<?php
/**
 * ICS 2371 — Lab 3: Control Structures I
 * Task 1: Temperature Alert System [8 marks]
 *
 * IMPORTANT: You must complete pseudocode AND flowchart in your PDF
 * report BEFORE writing any code below. Marks are awarded for all
 * three components: pseudocode, flowchart, and working code.
 *
 * @author     [Kevin Mutua]
 * @student    [ENE212-0078/2023]
 * @lab        Lab 3 of 14
 * @unit       ICS 2371
 * @date       [1 April 2026]
 */
// ══════════════════════════════════════════════════════════════
// EXERCISE A — Temperature Alert System
// ══════════════════════════════════════════════════════════════

// Change value to test 36.8, 39.2, and 34.5
$temperature = 39.2; 

// 1. Check for Normal range (inclusive: 36.1 to 37.5)
if ($temperature >= 36.1 && $temperature <= 37.5) {
    echo "Normal";
}

// 2. Check for Fever
if ($temperature > 37.5) {
    echo "Fever";
}

// 3. Check for Hypothermia Warning
if ($temperature < 36.1) {
    echo "Hypothermia Warning";
}


// ══════════════════════════════════════════════════════════════
// EXERCISE B — Even or Odd
// ══════════════════════════════════════════════════════════════

$number = 47;

// 1. Even or Odd Check
if ($number % 2 == 0) {
    echo "$number is EVEN<br>";
} else {
    echo "$number is ODD<br>";
}

// 2. Divisibility by 3
if ($number % 3 == 0) {
    echo "$number is divisible by 3<br>";
}else {
    echo "$number is not divisible by 3<br>";
}

// 3. Divisibility by 5
if ($number % 5 == 0) {
    echo "$number is divisible by 5<br>";
}else {
    echo "$number is not divisible by 5<br>";
}

// 4. Divisibility by both
if ($number % 3 == 0 && $number % 5 == 0) {
    echo "$number is divisible by both 3 and 5<br>";
}else {
    echo "$number is not divisible by both<br>";
}



// ==========================================
// Exercise C — Comparison Chain
// ==========================================
$x = 10;    // Integer
$y = "10";  // String
$z = 10.0;  // Float (Decimal)

echo "<h3>Exercise C Results:</h3>";
echo "<pre>"; // <pre> makes var_dump output easier to read in a browser

var_dump($x == $y);  // A
var_dump($x === $y); // B
var_dump($x == $z);  // C
var_dump($x === $z); // D
var_dump($y === $z); // E
var_dump($x <=> $y); // F

echo "</pre>";


// ==========================================
// Exercise D — Null & Default Values
// ==========================================
echo "<h3>Exercise D Results:</h3>";

// Part 1: Basic Null Coalescing
$username = null;
$display = $username ?? "Guest";
echo "Welcome, $display<br>";

// Part 2: Chained Null Coalescing
$config_val = null;
$env_val = null;
$default = "system_default";
$result = $config_val ?? $env_val ?? $default;
echo "Config: $result<br>";

// Part 3: My Custom Chained Example
// This checks for a user-set theme, then a session theme, then defaults to 'Light'
$user_theme = null;
$session_theme = "Dark Mode"; 
$fallback_theme = "Light Mode";

$final_theme = $user_theme ?? $session_theme ?? $fallback_theme;

echo "Selected Theme: $final_theme<br>";

?>