Fix: Deprecated: Required parameter follows optional parameter error PHP

The ‘Deprecated: Required parameter follows optional parameter’ error occurs in PHP 8.0+ when a required parameter is placed after an optional parameter in function declarations.

How the Error Happens

❌ Error Scenario:

<?php
// ❌ This causes the deprecation error
function createUser($name, $email = 'default@example.com', $age) {
    // PHP 8.0+: Deprecated: Required parameter $age follows optional parameter $email
}
?>

✅ Quick Fix - Order Function Parameters Properly

Solution 1: Reorder Parameters

<?php
// ✅ Move required parameters before optional ones
function createUser($name, $age, $email = 'default@example.com') {
    return "Name: $name, Age: $age, Email: $email";
}

// ✅ Usage
echo createUser('John', 25); // Name: John, Age: 25, Email: default@example.com
echo createUser('Jane', 30, 'jane@example.com'); // Name: Jane, Age: 30, Email: jane@example.com
?>

Solution 2: Make All Parameters Optional

<?php
// ✅ Provide defaults for all parameters
function createUser($name = '', $email = 'default@example.com', $age = 0) {
    return "Name: $name, Age: $age, Email: $email";
}

// ✅ Usage
echo createUser('John', 'john@example.com', 25);
?>

Solution 3: Use Null Coalescing Operator

<?php
// ✅ Use null coalescing for required parameters
function createUser($name, $email = null, $age = null) {
    $email = $email ?? 'default@example.com';
    $age = $age ?? 0;
    
    return "Name: $name, Age: $age, Email: $email";
}

// ✅ Usage
echo createUser('John', null, 25);
?>

Solution 4: Use Named Arguments (PHP 8.0+)

<?php
// ✅ Use named arguments to bypass parameter order
function createUser($name, $email = 'default@example.com', $age = 0, $role = 'user') {
    return "Name: $name, Age: $age, Email: $email, Role: $role";
}

// ✅ Usage with named arguments
echo createUser(
    name: 'John',
    age: 25,
    role: 'admin'
);
?>