filter_has_var

Please note that the function does not check the live array, it actually checks the content received by php:<?php$_GET['test'] = 1;echo filter_has_var(INPUT_GET, 'test') ? 'Yes' : 'No';?>would say "No", unless the parameter was actually in the querystring.Also, if the input var is empty, it will say Yes.

Through this example i think you can better understand    if ( !filter_has_var(INPUT_GET, 'email') ) {        echo "Email Not Found";    }else{        echo "Email Found";    }    Output    localhost/nanhe/test.php?email=1 //Email Found    localhost/nanhe/test.php?email //Email Found    http://localhost/nanhe/test.php //Email Not FoundConsider on second examplehttp://localhost/nanhe/test.php$_GET['email']="info@nanhe.in";if ( !filter_has_var(INPUT_GET, 'email') ) {        echo "Email Not Found";    }else{        echo "Email Found";    }But output will be Email Not Found