How does PHP handle typecasting for numeric values with leading zeros, and what implications does this have for data integrity?

When PHP typecasts a numeric value with leading zeros, it treats it as an octal number. This can lead to unexpected results, such as numbers being interpreted differently than intended. To ensure data integrity, it's important to explicitly convert these values to integers using functions like intval() or (int).

$number = "0123";
$intNumber = intval($number);
echo $intNumber; // Output: 123