How can PHP functions be optimized to return values instead of using echo statements for better code structure?

To optimize PHP functions to return values instead of using echo statements for better code structure, you can modify the function to return the desired value instead of directly outputting it with echo. This allows for better control over where and how the function's output is used, making the code more modular and easier to maintain.

// Before optimization
function calculateSum($num1, $num2) {
    $sum = $num1 + $num2;
    echo $sum;
}

// After optimization
function calculateSum($num1, $num2) {
    $sum = $num1 + $num2;
    return $sum;
}

// Usage
$sum = calculateSum(5, 3);
echo $sum; // Output: 8