Code Output:

Now, lets run our sample, and check whether it validate form data or not. Left all the fields blank with null values and try to submit, the form will immediately popup a message “UserName must be filled”.

Similarly, left the other fields blank and check whether it validate form and show appropriate message or not.

Server Side validation:

In this post you’ll learn Server side validation using PHP. Validation using PHP are considered to be more secure .PHP has a wide variety of functions and features which is used to validate a form.

<?php

//when the form is submmited it will insert the values entered by user

if(isset($_POST["submit"]))
{

       $uname=$_POST["uname"];

       $pass=$_POST["pass"];

       $name=$_POST["name"];

       $day = $_POST["day"];

       $month = $_POST['month'];

       $year = $_POST["year"];

       $dob= $year."-".$month."-".$day;

       $phone=$_POST["phone"];

//connection is made with database

$con = mysqli_connect("localhost","username",”password”, 'database name');

//It will insert the value in database which is enterd by the user 
       $con->query("insert into user_login values('$uname','$pass','$name','$dob',$phone)");

           if(empty($uname))//if username is empty than message would be given
                 {                       $msg= "Please enter Username";                 } 


             else
                { 
                       if(empty($pass)) //if password is empty than message would be given

                {

                 $msg= "Please enter Password";

                 } 

                 else  if(empty($name)) //if name is empty than message would be given
                 { 
                $msg= "Please enter Name";

                 }

               else if(empty($year)) //if Year is empty than message would be given
                 { 
                $msg= "Please enter Year"; 


                 }

         else  if(empty($month)) //if month is empty than message would be given
                {
                   $msg= "Please enter Month";

                 }
        else  if(empty($day)) //if Day is empty than message would be given
                 {

                   $msg= "Please enter Day";
                 }

        else   if(empty($phone)) //if phone is empty than message would be given
                 {

             ?>
           <strong style=background-color:red>Please enter Phone</strong>
           <?php

                 }

       }

}
?>

//Style is used in the form
<style>
input[type=text],input[type=number],input[type=password]
 {
    padding: 10px 20px;
    margin: 3px 0;
    display: inline-block;
    border: 1px solid #ccc;
    border-radius: 6px;
    box-sizing: border-box;
          marg
}
.user
{
   background-color:lightgrey;
   width:40%;
   margin-top:20px;
   }

</style>

 Code Output:

Now, lets run our sample, and check whether it validate form data or not. Left all the fields blank with null values and try to submit, the form will immediately popup a message “Please enter username”.

Similarly left the other fields blank and check whether it validate form and show appropriate message or not. 

Validation using Regular Expression (Server side):

We will show you how to validate names, e-mails and URL’s:

 PHP-Validate e-mails:

The code below show the validation in e-mail :

Step1: Create an HTML page email.php

<style>
.text                                    
{
     text-align:center;
           line-height:525px;
</style>
<form method="post" class="text">
<input type="text" name="email">
<input type="submit" name="sub">
</form>
<?php
requie_once(“validate.php”);

?>

 Step2: Create validate.php:

<?php
//when the form is submmited it will insert the values entered by user
if(isset($_POST["sub"]))
{
$email=$_POST["email"];
//the pattern is "any letter or number followed by @ followed by any letter or number
//followed by . followed by 2-4 letters and maybe another.
$okay = preg_match(

        '/^[A-z0-9_\-]+[@][A-z0-9_\-]+([.][A-z0-9_\-]+)+[A-z.]{2,4}$/', $email

);

if ($okay) {
    echo $email." is valid<br />";
} else {
    echo $email." is invalid<br />";

}
}
?>
</form>
 

Code Output:

Here is the output of e-mail validation:

PHP-Validate name:

The code below show the validation in name:

Step1: Create  an HTML page name.php

     <form method="post">

               Name: <input type="text" name="name">

      <span class="error"></span>

      <input type="submit" name="sub">

      </form>

<?php

 require_once(“validate.php”);

?>

 Step2: Create validate.php: 

<?php

  if(isset($_POST["sub"]))

{

  $name = $_POST["name"];

    // check if name only contains letters and whitespace

    if (!preg_match("/^[a-zA-Z ]*$/",$name)) {

      echo "Only letters and white space allowed";

    }

}



  ?>
 

Code Output:

When you will enter numbers, symbols or other than letters it will show a message “Only letters and white spaces are allowed”.

PHP-Validate number:

The code below show the validation in number:

Step1: Create  an HTML page number.php

  <form method="post">

    <input type="text" name="number">

    <input type="submit" name="submit">

</form>

<?php

require_once(“validate.php”);

?>

 Step2: Create validate.php

<?php

if(isset($_POST["submit"]))

{

    $num = $_POST['number'];

    if (!preg_match('/^[0-9]*$/', $num))

    {

        echo("Only number should be entered");

    } else

    {

       echo("Valid");

    }

}

?>

Code Output:

When you will enter letters, symbols or other than number it will show a message “Only number should be entered”.

PHP-Validate Password:

The code below show the validation in password:

Step1: Create  an HTML page password.php

<form method="post">

   <input type="text" name="password">

   <input type="submit" value="submit" name="submit">

</form>

<?php

require_once(“validate.php”);

?>

Step2: Create validate.php

<?php
if(isset($_POST["submit"]))
{

if(!empty($_POST["password"]) )
{

        $password = $_POST["password"]; 

        if (strlen($_POST["password"]) <= '8') {
            echo "Your Password Must Contain At Least 8 Characters!";
        }

        elseif(!preg_match("#[0-9]+#",$password)) {

            echo "Your Password Must Contain At Least 1 Number!";

        }
        elseif(!preg_match("#[A-Z]+#",$password)) {
             echo "Your Password Must Contain At Least 1 Capital Letter!";

        }

        elseif(!preg_match("#[a-z]+#",$password)) {

             echo "Your Password Must Contain At Least 1 Lowercase Letter!";

        }

    }
          }

          ?>

Code Output:

Your password must contain minimum 8 characters which include 1 uppercase letter, 1 lowercase and 1 number.