How can PHP developers ensure they are following best practices when manipulating numerical data in strings?

When manipulating numerical data in strings, PHP developers should ensure they are following best practices by using proper type casting and validation to avoid unexpected results or errors. One common mistake is performing arithmetic operations on strings without converting them to numbers first. To avoid this issue, developers should always use functions like intval() or floatval() to explicitly convert string values to numbers before performing any calculations.

// Example of converting a string to a number before performing arithmetic operations
$number1 = "10";
$number2 = "20";

$sum = intval($number1) + intval($number2);
echo $sum; // Output: 30