PHP Check Function - php

Question

I have a check function:
function checkCandidateEmail($email)
{
$email = $_POST;
if($email)
{
$candemail = (SQL);
if(isset($candemail['email']))
{
return TRUE;
} else {
return FALSE;
}
return $canEmailCheck;
}
}
I have started to create a function but I am getting NULL

Answer 1

function checkCandidateEmail($email)
{
$email = $_POST; // being immediately overwritten - redundant argument.
if($email) // Since $email isn't an optional argument, you'll get a PHP warning if it is missing, making this check confusing.
{
$candemail = (SQL); // Evaluating a constant? this will be bool
if(isset($candemail['email'])) // Since $candemail is a bool and not an array, this will never return true
{
return TRUE;
} else {
return FALSE;
} // this entire if/else block can be simplified to this: return (isset($candemail['email']));
return $canEmailCheck; // this is an undefined variable and will never get returned anyway because of the above return statements.
}
}

Answer 2

Please, elaborate more on your questions next time. I am not sure what you attempt to compare, if the $_POST with the SQL query or the argument passed with the SQL query. I assume the former.
If the email from that SQL table row equals the submitted email, returns TRUE. Else, returns FALSE. Really simplified version. Now it also checks if the user provided an email:
function checkCandidateEmail()
{
if (!$_POST['email']) echo "Error, please provide an email";
else
{
$candemail = (SQL); // Return a row from a query
return $candemail['email'] == $_POST['email'];
}
}
If an argument is passed, compares that against the database. If none is passed, compares the submitted $_POST['email'] against the database.
function checkCandidateEmail($email=null)
{
$candemail = (SQL); // Return a row from a query
if (!$email) $email = $_POST['email'];
return $candemail['email'] == $email;
}
NOTE: In both cases you have to substitute SQL for the right string and function depending on your database.
NOTE 2: Make sure that your query returns an email, as this simple code does not check if both strings are empty.