[php] Calling a particular PHP function on form submit

I was trying to call a particular php function in submit of a form both the form and php scripts are in same page. My code is below.(it is not working and so I need help)

<html>
    <body>
    <form method="post" action="display()">
        <input type="text" name="studentname">
        <input type="submit" value="click">
    </form>
    <?php
        function display()
        {
            echo "hello".$_POST["studentname"];
        }
    ?>
    </body>
</html>

This question is related to php isset

The answer is


If you want to call a function on clicking of submit button then you have
to use ajax or jquery,if you want to call your php function after submission of form you can do that as :

<html>
<body>
<form method="post" action="display()">
<input type="text" name="studentname">
<input type="submit" value="click">
</form>
<?php
function display()
{
echo "hello".$_POST["studentname"];
}
if($_SERVER['REQUEST_METHOD']=='POST')
{
       display();
} 
?>
</body>
</html>

An alternative, and perhaps a not so good procedural coding one, is to send the "function name" to a script that then executes the function. For instance, with a login form, there is typically the login, forgotusername, forgotpassword, signin activities that are presented on the form as buttons or anchors. All of these can be directed to/as, say,

weblogin.php?function=login
weblogin.php?function=forgotusername
weblogin.php?function=forgotpassword
weblogin.php?function=signin

And then a switch statement on the receiving page does any prep work and then dispatches or runs the (next) specified function.


Write this code

<?php
    if(isset($_POST['submit'])){
        echo 'Hello World';
    } 
?>

<html>
     <body>
         <form method="post">
             <input type="text" name="studentname">
             <input type="submit" name="submit" value="click">
         </form>
     </body>
</html>

PHP is run on a server, Your browser is a client. Once the server sends all the info to the client, nothing can be done on the server until another request is made.

To make another request without refreshing the page you are going to have to look into ajax. Look into jQuery as it makes ajax requests easy


Assuming that your script is named x.php, try this

<?php 
   function display($s) {
      echo $s;
   }
?>
<html>
    <body>
        <form method="post" action="x.php">
            <input type="text" name="studentname">
            <input type="submit" value="click">
        </form>
        <?php
           if($_SERVER['REQUEST_METHOD']=='POST')
           {
               display();
           } 
        ?>
    </body>
</html>

you don't need this code

<?php
function display()
{
echo "hello".$_POST["studentname"];
}
?>

Instead, you can check whether the form is submitted by checking the post variables using isset.

here goes the code

if(isset($_POST)){
echo "hello ".$_POST['studentname'];
}

click here for the php manual for isset