What potential factors, such as leading spaces or line breaks, can affect typecasting in PHP?

Leading spaces or line breaks in a variable can affect typecasting in PHP because they can interfere with the conversion process. To solve this issue, you can use the `trim()` function to remove any leading or trailing spaces from the variable before typecasting it.

// Example of typecasting with leading spaces removed
$variable = "   123";
$integer = (int)trim($variable);
echo $integer; // Output: 123