How to Create a PHP Form Validation (isset and empty function)

What Will I Learn?

You will learn how to create form validation
You will learn how make your database more valid
you will learn how to make secure website

Requirements

you must understand PHP basic programming
you must know how to implement isset and empty function
you must understand how to create form structure

Difficulty

Intermediate

Tutorial Contents

validation process is needed on a website form, function so that the data inputted into the database of your website becomes more valid, would make it easier if you want to create a report data from your website because there is no wrong data format.

Okay, just start our tutorial.
first you have to open the text editor, i suggest you to use notepad ++ as i use so this tutorial is easy to understand.
then create two files, form.php file and warning.php file
form.php file serves as the form where we fill in the data, and warning.php file serves as a warning if the form is not filled correctly.
type the script below and intersect with the name form.php

<!DOCTYPE html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>utopian-io tutorial</title>
</head>
<body>
<h2>how to create validation form </h2>
<form action="proses.php" method="get">
NAME: <input type="text" name="nama" />
<br/>
E-Mail: <input type="text" name="email" />
<br/>
<input type="submit" value="Proses Data" >
</form>
</body>
</html>

I will explain a bit about the script above
This script serves as an account to the warning.php page
<form action="warning.php" method="get">
then for the design of the form we use the script below

<form action="warning.php" method="get">
NAME: <input type="text" name="nama" />
<br/>
E-Mail: <input type="text" name="email" />
<br/>
<input type="submit" value="Proses Data" >
</form>

then we will create a warning page, type the script below and save it with the name warning.php

<?php
if (isset($_GET['name']) AND isset($_GET['email']))
{
$nama=$_GET['name'];
$email=$_GET['email'];
}
else
{
die("sorry, you must acces this page from form.html page");
}
  
if(empty($name))
{
die("sorry, you must enter your name");
}
else
{
if (is_numeric($name))
{
die("sorry, name must containing alphabet");
}
else
{
echo "Nama: $name 
 Email: $email";
}
}
?>

I will explain about the script above
this serves as a warning if the form is not filled

if(empty($name))
{
die("sorry, you must enter your name");
}

then this as a warning if the variable name has no letter character in it

if (is_numeric($name))
{
die("sorry, name must containing alphabet");
}

This is a script that serves to display a warning when we access the file warning.php without entering the form page first.

else
{
die("sorry, you must acces this page from form.html page");
}

now we try to run the form we have created, whether it is working like yag we want.
run the file form.html by typing the filename in your browser search field as shown below.

the form already appears

now to try it we will hit the submit button without filling the data first we see whether to perform warning.

error message

then we try to fill in the name with a number character.

then press submit button

Let's see what will come up

error format message

now we try to run the file warning.php without accessing the file form.html first. we'll see what will come up.

warning that we access the file form.html first