Data Accessing Functions mixed filter_input (int source, string name, string filter [, mixed filter_options, [ string characterset ] ]); Returns the filtered variable $name from source $source. It uses the filter as specified in $filter, and additional options to the filter through $filter_options. bool filter_var (mixed variable, string filter [, mixed filter_options, [ string characterset ] ]); Filters the user supplied variable $variable with the filter $filter using the options as specified in $filter_options. This function modifies the original variable, and returns false if the filter failed, or true if it was succesfull.