What are some common PHP functions that can be used for automatic corrections in user input, such as replacing commas with periods?

When dealing with user input, it is common to encounter formatting inconsistencies that may need to be corrected for consistency or proper processing. One common issue is replacing commas with periods in numerical input. This can be achieved using PHP's str_replace() function, which allows you to search for a specific character (in this case, a comma) and replace it with another character (a period).

$user_input = "1,000,000.50";
$corrected_input = str_replace(",", ".", $user_input);
echo $corrected_input;