Is there a better way to validate my form? PHP - php

Question

I am trying to create a register page and I was wondering if there is a better way of doing this. So what I was think was instead of typing every field or is this a good way of doing this?
This is what I have currently.
This is the form
<form action="" method="POST">
<input type="text" name="username" placeholder="Username:" />
<input type="password" name="password" placeholder="Password:" />
<input type="password" name="password" placeholder="Confirm password:" />
<input type="text" name="email" placeholder="Email:" />
<input type="text" name="first_name" placeholder="First name:" />
<input type="text" name="last_name" placeholder="Last name:" />
<input type="submit" name="register" value="REGISTER" />
</form>
This is what I have for PHP side
function reg_validation() {
if ($_POST['register']) {
if (empty($_POST['username'])) {
echo 'Please enter a username';
}
if (empty($_POST['password'])) {
echo 'Please enter a password';
}
if (empty($_POST['confirm_password'])) {
echo 'Please confirm your password';
}
if (empty($_POST['email'])) {
echo 'Please enter an email address';
}
if (empty($_POST['first_name'])) {
echo 'Please enter your first name';
}
if (empty($_POST['last_name'])) {
echo 'Please enter your last name';
}
}
}

Answer 1

<?php
function reg_validation() {
if (isset($_POST['register'])) {
$expectedFields = array(
'username', 'password', 'confirm_password', 'email', 'first_name', 'last_name'
);
foreach ($expectedFields as $value)
if (!array_key_exists($value, $_POST) || empty($_POST[$value]))
return false;
return true;
}
return false;
}
?>
Don't know if I misunderstood your question in my last answer, so here is another suggestion. Code is not tested, so it may contain minor typos.
In this suggestion we store all field names in an array an loop through the array and checks if any of the field names is not a key in the post array.
So this function will return true if all fields is found in post data or false if not.

Answer 2

<?php
if (isset($_POST['register'])) {
try {
if (empty($_POST['username']))
throw new Exception('missing_username');
else if (empty($_POST['password']))
throw new Exception('missing_password');
else if (empty($_POST['confirm_password']))
throw new Exception('missing_confirm_pass');
else if (empty($_POST['email']))
throw new Exception('missing_email');
else if (empty($_POST['first_name']))
throw new Exception('missing_firstname');
else if (empty($_POST['last_name']))
throw new Exception('missing_lastname');
// do something if all fields are filled
} catch (Exception $e) {
$errorArray = array(
'missing_username' => 'Please enter a username',
'missing_password' => 'Please enter a password',
'missing_confirm_pass' => 'Please confirm your password',
'missing_email' => 'Please enter an email address',
'missing_firstname' => 'Please enter your first name',
'missing_lastname' => 'Please enter your last name'
);
if (isset($errorArray[$e->getMessage()]))
echo $errorArray[$e->getMessage()];
}
}
?>
I like to do it this way, don't know what everyone else thinks about it.
By using try catch, we don't neccessarily need a function to return, since we instead can throw an exception to break from the try section.