ctype_xdigit
Introduction
Variable and Type Related Extensions
PHP Manual
Data Filtering
Introduction
Installing/Configuring
Requirements
Installation
Runtime Configuration
Resource Types
Types of filters
Validate filters
Sanitize filters
Other filters
Filter flags
Predefined Constants
Examples
Validation
Sanitization
Filter Functions
filter_has_var
— Checks if variable of specified type exists
filter_id
— Returns the filter ID belonging to a named filter
filter_input_array
— Gets external variables and optionally filters them
filter_input
— Gets a specific external variable by name and optionally filters it
filter_list
— Returns a list of all supported filters
filter_var_array
— Gets multiple variables and optionally filters them
filter_var
— Filters a variable with a specified filter
ctype_xdigit
Introduction
Variable and Type Related Extensions
PHP Manual