Php/docs/filter.examples.validation
Validation
Example #1 Validating email addresses with filter_var()
<?php$email_a = 'joe@example.com';$email_b = 'bogus';if (filter_var($email_a, FILTER_VALIDATE_EMAIL)) { echo "Email address '$email_a' is considered valid.\n";}if (filter_var($email_b, FILTER_VALIDATE_EMAIL)) { echo "Email address '$email_b' is considered valid.\n";} else { echo "Email address '$email_b' is considered invalid.\n";}?>
以上例程会输出：
Email address 'joe@example.com' is considered valid. Email address 'bogus' is considered invalid.
Example #2 Validating IP addresses with filter_var()
<?php$ip_a = '127.0.0.1';$ip_b = '42.42';if (filter_var($ip_a, FILTER_VALIDATE_IP)) { echo "IP address '$ip_a' is considered valid.";}if (filter_var($ip_b, FILTER_VALIDATE_IP)) { echo "IP address '$ip_b' is considered valid.";}?>
以上例程会输出：
IP address '127.0.0.1' is considered valid.
Example #3 Passing options to filter_var()
<?php$int_a = '1';$int_b = '-1';$int_c = '4';$options = array( 'options' => array( 'min_range' => 0, 'max_range' => 3, ));if (filter_var($int_a, FILTER_VALIDATE_INT, $options) !== FALSE) { echo "Integer A '$int_a' is considered valid (between 0 and 3).\n";}if (filter_var($int_b, FILTER_VALIDATE_INT, $options) !== FALSE) { echo "Integer B '$int_b' is considered valid (between 0 and 3).\n";}if (filter_var($int_c, FILTER_VALIDATE_INT, $options) !== FALSE) { echo "Integer C '$int_c' is considered valid (between 0 and 3).\n";}$options['options']['default'] = 1;if (($int_c = filter_var($int_c, FILTER_VALIDATE_INT, $options)) !== FALSE) { echo "Integer C '$int_c' is considered valid (between 0 and 3).";}?>
以上例程会输出：
Integer A '1' is considered valid (between 0 and 3). Integer C '1' is considered valid (between 0 and 3).
