How to Validate Form Data With PHP

0 votes
Want to know what is the generic code i can used using php to validate  from data?
Feb 13, 2020 in PHP by kartik
• 37,510 points
1,891 views

1 answer to this question.

0 votes

Hey @kartik,

The first thing we will do is to pass all variables through PHP's htmlspecialchars() function.

When we use the htmlspecialchars() function; then if a user tries to submit the following in a text field:

<script>location.href('http://www.hacked.com')</script>

- this would not be executed, because it would be saved as HTML escaped code, like this:

&lt;script&gt;location.href('http://www.hacked.com')&lt;/script&gt;

The code is now safe to be displayed on a page or inside an e-mail.

We will also do two more things when the user submits the form:

  1. Strip unnecessary characters (extra space, tab, newline) from the user input data (with the PHP trim() function)
  2. Remove backslashes (\) from the user input data (with the PHP stripslashes() function)

The next step is to create a function that will do all the checking for us (which is much more convenient than writing the same code over and over again).

We will name the function test_input().

Now, we can check each $_POST variable with the test_input() function, and the script looks like this:

Example

<?php
// define variables and set to empty values
$name = $email = $gender = $comment = $website = "";

if ($_SERVER["REQUEST_METHOD"] == "POST") {
  $name = test_input($_POST["name"]);
  $email = test_input($_POST["email"]);
  $website = test_input($_POST["website"]);
  $comment = test_input($_POST["comment"]);
  $gender = test_input($_POST["gender"]);
}

function test_input($data) {
  $data = trim($data);
  $data = stripslashes($data);
  $data = htmlspecialchars($data);
  return $data;
}
?>

If you want to know how can we avoid my php form from hacking check it out-  PHP Security

answered Feb 13, 2020 by Niroj
• 82,840 points

Related Questions In PHP

0 votes
1 answer

How to validate E-mail and URL of Php form?

hey, The code below shows a simple way ...READ MORE

answered Feb 13, 2020 in PHP by manish
1,383 views
0 votes
0 answers

How to run a PHP function due to a button click (with button 'data' passed)?

I manage some sortiment items on a ...READ MORE

May 28, 2022 in PHP by Kichu
• 19,040 points
2,857 views
0 votes
0 answers

How to retrieve data from multiple tables using a PHP form?

I want to retrieve data from multiple ...READ MORE

Jun 25, 2022 in PHP by narikkadan
• 52,400 points
771 views
0 votes
0 answers

How to extract and access data from JSON with PHP?

This is intended to be a general ...READ MORE

Jul 22, 2022 in PHP by narikkadan
• 52,400 points
325 views
+1 vote
1 answer

What is the relationship between angularjs Scope with controller/view?

Let us consider the below block: <div ng-controller="emp"> ...READ MORE

answered Jan 20, 2020 in Web Development by Niroj
• 82,840 points

edited Jan 21, 2020 by Niroj 515 views
+1 vote
1 answer

What is css box module?

Hey, All the element present in html follows ...READ MORE

answered Jan 20, 2020 in Web Development by Niroj
• 82,840 points

edited Jan 21, 2020 by Niroj 611 views
0 votes
3 answers

Explain the difference between visibility:hidden; and display:none?

display:none means that the tag in question will ...READ MORE

answered Dec 14, 2020 in Web Development by Gitika
• 65,910 points
103,713 views
+1 vote
1 answer

How to access the Angularjs scope of a particular html element from our console?

Hello, You should follow the below steps:-- 1.Compile and ...READ MORE

answered Jan 21, 2020 in Web Development by Niroj
• 82,840 points

edited Jan 21, 2020 by Niroj 1,506 views
0 votes
1 answer

What is a Cookie? How to create Cookies With PHP?

A cookie is often used to identify ...READ MORE

answered Feb 13, 2020 in PHP by Niroj
• 82,840 points
2,514 views
0 votes
1 answer

How to retrieve or obtain data from the MySQL database using PHP?

Hello kartik,  Actually there are many functions that  ...READ MORE

answered Mar 27, 2020 in PHP by Niroj
• 82,840 points
1,879 views
webinar REGISTER FOR FREE WEBINAR X
REGISTER NOW
webinar_success Thank you for registering Join Edureka Meetup community for 100+ Free Webinars each month JOIN MEETUP GROUP