CODEWITHSUNDEEP
php
uddipana
uddipana

Reputation: 188

keep the previous value of variable after submitting the form in php

I have a form with a button "NEXT", which on clicked needs to change the value of a variable.I have initialized the variable as 0 and I want that as the NEXT button is getting clicked the variable should increment by 1.Since, I am also submitting the form when the button is clicked,so the variable is resetting to 0,it is not keeping the previous value.

html code is :

       <form name="graph" enctype="multipart/form-data" method="POST" action="graph.php">   
       <input type="hidden" id="hdn" name ="hdn" value="">
        <input type="button" id="btnNext" name ="btnNext" value="NEXT" onClick="nextfun();">

Onclicking NEXT, I am calling a javascript function that is submitting the form,

       function nextfun()
       {
            var a= document.getElementById("hdn");
                a.value="nextgroup";
               document.graph.submit();
       }

Now,when form is submitted, I am using php code to increment the value of variable.

     $flag=0;
   if(isset($_POST['hdn']))
    {
       if($_POST["hdn"]=="nextgroup")
         {
            $flag=$flag+1;
          }
     }

Upvotes: 1

Views: 5819

Answers (2)

Death-is-the-real-truth
Death-is-the-real-truth

Reputation: 72299

On the graph.php page do like this:-

<?php
session_start();
if(isset($_POST['hdn']))
    {
       if($_POST["hdn"]=="nextgroup")
         {
            if(isset($_SESSION['flag'])){
                $_SESSION['flag'] = $_SESSION['flag']+1;
            }else{
                $_SESSION['flag'] = 1;
            }
          }
     }
echo $_SESSION['flag'];
?>

Note:- first time Session value will 1and nxt onward on each submission it will increase by 1.

Upvotes: 1

Gonz
Gonz

Reputation: 1219

You can add to your HTML something like this:

<input type="hidden" name="prevValue" value="<?php echo $prev; ?>" />

You should submit this value too.

And in the PHP

         $flag=0;
       if(isset($_POST['hdn']))
        {
           if($_POST["hdn"]=="nextgroup")
             {
                $prev = $_POST["prevValue"];
                $flag = $prev +1;
              }
         }

Upvotes: 0

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