How can the performance implications of call-by-reference in PHP functions be mitigated?

When using call-by-reference in PHP functions, it can have performance implications as it involves passing variables by reference which can lead to additional memory usage and slower execution. To mitigate these performance issues, it is recommended to avoid using call-by-reference unless necessary and instead pass variables by value. This can help improve the efficiency of the code and reduce memory overhead.

// Pass variables by value instead of by reference to improve performance
function modifyValue($value) {
    $value += 10;
    return $value;
}

$number = 5;
$modifiedValue = modifyValue($number);
echo $modifiedValue; // Output: 15