Php: built-in method for verifying whether the mailbox, URL, and IP address are valid

PHP verifies whether the mailbox, URL, and IP address are valid. Previously, PHP verifies whether the mailbox, URL, and IP address are valid through self-writing regular expressions, it is possible to write a regular expression that is not completely correct, leading to verification errors. Today, it is found that PHP itself contains a function to verify whether the mailbox, URL, and IP address are valid. The main use is filter_var.

PHP verifies whether the mailbox, URL, and IP address are valid. Previously, PHP verifies whether the mailbox, URL, and IP address are valid through self-writing regular expressions, it is possible to write a regular expression that is not completely correct, leading to verification errors. Today, it is found that PHP itself contains a function to verify whether the mailbox, URL, and IP address are valid. The main use is filter_var.

Verify the mailbox, URL, and IP address with PHP
In the past, PHP was used to verify whether the mailbox, URL, and IP address are valid by writing regular expressions. However, sometimes the brain is dizzy and may write an incorrect regular expression, leading to verification errors, today, we found that PHP has built-in functions to verify the validity of email addresses, URLs, and IP addresses.

The filter_var function is mainly used.

Syntax
Filter_var(Variable, filter, options)
Parameter description
Variable is required. Specifies the variable to be filtered.
Optional. Specifies the ID of the filter to be used.
Options specifies an array containing flag/option. Check the possible flags and options of each filter.

PHP Filters

ID	Description
FILTER_CALLBACK	You can call a user-defined function to filter data.
FILTER_SANITIZE_STRING
FILTER_SANITIZE_STRIPPED	The alias of the "string" filter.
FILTER_SANITIZE_ENCODED	URL-encode string to remove or encode special characters.
FILTER_SANITIZE_SPECIAL_CHARS	HTML Escape Character '"<> & characters with ASCII value less than 32.
FILTER_SANITIZE_EMAIL	Delete all characters except letters, numbers, and! # $ % & '* +-/=? ^ _ '{| }~ @. []
FILTER_SANITIZE_URL	Delete all characters except letters, numbers, and $-_. +! * '(), {}|\\^ ~ [] '<> # % ";/? : @ & =
FILTER_SANITIZE_NUMBER_INT	Delete all characters except numbers and +-
FILTER_SANITIZE_NUMBER_FLOAT	Delete all characters except numbers, +-, and., eE.
FILTER_SANITIZE_MAGIC_QUOTES	Apply addslashes ().
FILTER_UNSAFE_RAW	Do not filter, remove, or encode special characters.
FILTER_VALIDATE_INT	The value is verified by an integer in the specified range.
FILTER_VALIDATE_BOOLEAN	If it is "1", "true", "on", and "yes", true is returned. If it is "0", "false", "off ", "no" and "", false is returned. Otherwise, NULL is returned.
FILTER_VALIDATE_FLOAT	Verify the value with a floating point number.
FILTER_VALIDATE_REGEXP	Verify the value based on regexp and Perl-Compatible Regular Expressions.
FILTER_VALIDATE_URL	Use the value as the URL for verification.
FILTER_VALIDATE_EMAIL	Use the value as email for verification.
FILTER_VALIDATE_IP	Use the value as the IP address for verification.

Example:

The above routine will output:

string(15) "bob@example.com"bool(false)