How can the PHP code be optimized for efficiency without compromising readability for beginners?

To optimize PHP code for efficiency without compromising readability for beginners, it is important to focus on writing clean and concise code, avoiding unnecessary loops or function calls, and utilizing built-in PHP functions effectively. Additionally, using proper variable naming conventions and commenting the code can also improve readability for beginners.

// Example of optimized PHP code for efficiency and readability

// Before optimization
$sum = 0;
for($i = 1; $i <= 100; $i++) {
    $sum += $i;
}
echo $sum;

// After optimization
$sum = (1 + 100) * 100 / 2;
echo $sum;