06_conditionals.php

<?php

$age = 20;
$salary = 300000;

//// 1. if condition
//if ($age < 22) {       // 1.1 Without curly braces { }
//    echo 'You are young man!!<br>';
//}
//
//// 2. if condition - else
//if ($age < 22) {
//    echo 'You are young man!!<br>';
//} else {
//    echo 'You are not young man!!<br>';
//}
//
//// 3. if condition1 AND condition2
//if ($age < 22 && $salary > 500000) {
//    echo 'You are young AND rich<br>';
//}
//
//// 4. if condition1 OR condition2
//if ($age < 22 || $salary > 500000) {
//    echo 'You are young OR rich<br>';
//}
//
//// 5. if condition1 - elseif condition2 - else
//if ($age < 22) {
//    echo 'You are young man!!<br>';
//} elseif ($age > 60) {
//    echo 'You are old<br>';
//} else {
//    echo "You are not young, but not old also<br>";
//}
//// 6. if condition1 and condition2 - elseif condition1 and condition2 - else
//if ($age < 22 && $salary >= 500000) {
//    echo 'You are young man AND rich!!<br>';
//} elseif ($age < 22 && $salary < 500000) {
//    echo "You are young, and not so rich<br>";
//} elseif ($age > 60 && $salary >= 500000) {
//    echo 'You are old, but rich<br>';
//} elseif ($age > 60 && $salary < 500000) {
//    echo 'You are old and NOT rich also<br>';
//}

// 7. Ternary if
echo $age < 22 ? 'Young' : 'Old';
echo '<br>';
// 7.1 Nested ternary
echo $age < 22 ? ($age < 16 ? 'Too young' : 'Young') : 'Old';
echo '<br>';
// 7.2 Short ternary
$myAge = $age ?: 18; // Equivalent of "$age ? $age : 18"

// 8. Null coalescing operator
$var = isset($name) ? $name : 'John';
$var = $name ?? 'John'; // Equivalent of above
echo $var.'<br>';

// 9. Null coalescing assignment operator. Since PHP 7.4
$person = [
    'name' => 'John' // 9.1 Comment this line
];
if (!isset($person['name'])){
    $person['name'] = 'Anonymous';
}
$person['name'] ??= 'Anonymous';
echo $person['name'].'<br>';

// 10. switch
$userRole = 'admin'; // admin, editor, user

switch ($userRole) {
    case 'admin':
        echo 'You can do anything<br>';
        break;
    case 'editor';
        echo 'You can edit content<br>';
        break;
    case 'user':
        echo 'You can view posts and comment<br>';
        break;
    default:
        echo 'Unknown role<br>';
}