Validating various input HTML forms

Question

I'm looking for a review of my code for better design (to make sure it's more readable and legible).

<?php
// define variables and set to empty values
$nameErr = $phoneErr = $streetErr = $cityErr = $stateErr = $zipErr = "";
$name = $phone = $street = $city = $state = $zip = "";
// start script if the form is submitted
if ($_SERVER["REQUEST_METHOD"] == "POST") {
 if (empty($_POST["name"])) {
 $nameErr = "Name is required";
 }
 else {$name = test_input($_POST["name"]);
 // check if name only contains letters and whitespaces
 if (!preg_match("/^[a-zA-Z ]*$/",$name)) {
 $nameErr = "Only letters and white space allowed"; 
 }
}
 if (empty($_POST["phone"])) {
 $phoneErr = "Phone # is required";
 }
 else {$email = test_input($_POST["phone"]);
 // check if phone only contains numbers and dashes in correct format
 if (!preg_match("/^[0-9]{3}-[0-9]{3}-[0-9]{4}$/",$phone)) {
 $phoneErr = "Please resubmit Phone # in the following format: 555- 555-5555"; 
 }
 }
 if (empty($_POST["street"])) {
 $streetErr = "Address is required";
 }
 else {$street = test_input($_POST["street"]);
 // check if address syntax is valid
 if (!preg_match("/^[0-9a-zA-Z. ]+$/",$street)) {
 $streetErr = "Address appears to be invalid.";
 }
 }
 if (empty($_POST["city"])) {
 $cityErr = "City is required";
 }
 else {$city = test_input($_POST["city"]);
 // check if city syntax is valid
 if (!preg_match("/^[a-zA-Z ]*$/",$city)) {
 $cityErr = "City appears to be invalid." ; 
 }
 }
 if (empty($_POST["state"])) {
 $stateErr = "State is required";
} 
 else {$state = test_input($_POST["state"]);
 // check if state is valid uppercase abbv. and two letters
 if (!preg_match("/^(A[LKSZRAP]|C[AOT]|D[EC]|F[LM]|G[AU]|HI|I[ADL N]
 |K[SY]|LA|M[ADEHINOPST]|N[CDEHJMVY]|O[HKR]|P[ARW]|RI|S[CD] 
 |T[NX]|UT|V[AIT]|W[AIVY])$/",$state)) {
 $stateErr = "State appears to be invalid. (Hint...Use Upper-case!)" ; 
 }
}
if (empty($_POST["zip"])) {
 $zipErr = "Zip Code field is required";
} 
else {$zip = test_input($_POST["zip"]);
 // check if zip only contains numbers and dashes in correct format
 if (!preg_match("/^[0-9]{5}-[0-9]{4}$/",$phone)) {
 $phoneErr = "Please resubmit Zip Code in the following format: 55555-5555"; 
 }
}
}
function test_input($data) {
 $data = trim($data);
 $data = stripslashes($data);
 $data = htmlspecialchars($data);
 return $data;
}
?>

• Jamal: Welcome. Could you please describe this code for better context? Does it work as intended? If it does work, what type(s) of review are you seeking?
• matheussilvapb: What does your test_input function does ?
• user42910: The code works yes, this code validates various input HTML forms. I was looking for a markup of my code for better structure of the syntax. (to make it more readable and legible)
• matheussilvapb: Make sure your code is not vulnerable to PHP injection, you should use htmlspecialchars()

Answer 1

1. you should be using arrays to store your variable.

2. your coding if syntax are not indented and formatted well.
   https://stackoverflow.com/questions/253030/best-way-to-format-if-statement-with-multiple-conditions

3. it is better to use

   if ($_POST) { }

   /** rather than **/

   if ($_SERVER["REQUEST_METHOD"] == "POST") { }

in your case.

if anything else read about PSR1 or PSR2 coding standard.

1. http://www.php-fig.org/psr/psr-1/
2. http://www.php-fig.org/psr/psr-2/