This document discusses form validation using built-in PHP functions. It covers metacharacters used for validation like \w, \W, \d, and \D. The main function discussed is filter_var(), which filters variables with specified filters. Examples are given of using filter_var() to validate integers, integers within a range, strings with regular expressions, and email addresses.

1. FORM VALIDATION
BUILT-IN FUNCTIONS

2. TOPICS TO BE COVERED
• Metacharacters
• Php Function filter_var()
muhammadabaloch

3. METACHARACTERS
• Metacharacters are characters with a special meaning:
Metacharacter Description
w Finds word character i.e. (alphabets and
number)
W Finds non-word character i.e. (Special
Characters)
d Finds digit i.e. (Numbers)
D Finds non-digit character i.e. (alphabets
and Special Characters)
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4. METACHARACTERS
$string = "ali123"; // Characters+ number
$patt = "/w/";
$string = "$ _-+"; // Special Characters
$patt = "/W/";
$string = "$*&"; // number
$patt = "/d/"; // return false
$string = “1234"; //alphabets and Special Characters
$patt = "/D/";
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5. PHP FUNCTION filter_var()
• The filter_var() function filters a variable with the specified filter.
• Returns the filtered data on success or FALSE on failure.
Syntax
filter_var( variable , filter , options )
Parameter Description
variable Required. Specifies the variable to filter
filter Optional. Specifies the ID of the filter to
use. Default is FILTER_SANITIZE_STRING.
options Optional. Specifies an associative array of
flags/options or a single flag/option. Check
each filter for possible options and flags
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6. PHP FUNCTION filter_var()
• Number (Integer) Validation
• Number (Integer) validation with range
• Validation String with Regular Expression
• Email Validation
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7. PHP FUNCTION filter_var()
• Number (Integer) Validation
<?php
$integer="6234";
if( filter_var ( $integer , FILTER_VALIDATE_INT ) ) {
echo "Integer Number";
}
else {
echo "Not Integer";
}
?>
muhammadabaloch

8. PHP FUNCTION filter_var()
• Number (Integer) Validation with range
<?php
$integer ="6234";
if( filter_var( $integer , FILTER_VALIDATE_INT,
array( "options"=>array("min_range"=>1,"max_range"=>5000 ) ) ) )
{
echo "Integer Number";
}else {
echo "Not Integer";
}
?>
muhammadabaloch

9. PHP FUNCTION filter_var()
• String Validation with Regular Expression
<?php
$string = “hidaya trust”;
$regExp = "/^[a-zA-Z ]{1,}$/";
if((filter_var($string,FILTER_VALIDATE_REGEXP,
array("options"=>array("regexp"=>$regExp)))))
{
echo "Expression Matched";
}
else {
echo "Expression Not Matched";
}
?> muhammadabaloch

10. PHP FUNCTION filter_var()
• Email Validation
<?php
$email = “shoro_asif@yahoo.com";
if(filter_var( $email, FILTER_VALIDATE_EMAIL )) {
echo "Valid Email";
}
else{
echo "invalid Email";
}
?>
muhammadabaloch