PHP Filter
Introduction to PHP Filter
PHP filters are used to validate and filter data from non-secure sources (such as user input).
Installation
The Filter function is an integral part of the PHP core. No installation is required to use these functions.
PHP Filter Function
PHP: Indicates the earliest PHP version that supports this function.
| Function | Description | PHP |
|---|---|---|
| filter_has_var() | Check whether a variable of the specified input type exists. | 5 |
| filter_id() | Returns the ID number of the specified filter. | 5 |
| filter_input() | Get input from outside the script and filter it. | 5 |
| filter_input_array() | Get multiple inputs from outside the script and filter them. | 5 |
| filter_list() | Returns an array containing all supported filters. | 5 |
| filter_var_array() | Get multiple variables and filter them. | 5 |
| filter_var() | Get a variable and filter it. | 5 |
PHP Filters
| ID Name | Description |
|---|---|
| FILTER_CALLBACK | Call user-defined functions to filter data. |
| FILTER_SANITIZE_STRING | Remove tags, remove or encode special characters. |
| FILTER_SANITIZE_STRIPPED | "string" Alias for the filter. |
| FILTER_SANITIZE_ENCODED | URL-encode string, remove or encode special characters. |
| FILTER_SANITIZE_SPECIAL_CHARS | HTML escape character '"<>& and characters with ASCII value less than 32. |
| FILTER_SANITIZE_EMAIL | Remove all characters except letters, numbers and !#$%&'*+-/=?^_`{|}~@.[] |
| FILTER_SANITIZE_URL | Remove all characters except letters, numbers and $-_.+!*'(),{}|\^~[]`<>#%";/?:@& = |
| FILTER_SANITIZE_NUMBER_INT | Remove all characters except numbers and +- |
| Remove all Characters, except numbers, +- and .,eE | |
| Apply addslashes(). | |
| Does not do any filtering, remove or encode special characters. | |
| Validate the value as an integer. | |
| Validate the value as a Boolean option. Returns TRUE if "1", "true", "on", and "yes". Returns FALSE if "0", "false", "off", "no", and "". Otherwise NULL is returned. | |
| Validate the value as a floating point number. | |
| Validate values against regexp, a Perl-compatible regular expression. | |
| Validate the value as a URL. | |
| Validate the value as an e-mail address. | |
| Validate the value as an IP address, only IPv4 or IPv6 or not from a private or reserved range. |
