Incrementing the value of the post by every repeated form submission - php

Question

I have a form sender which is posting a value of 6 to another form receiver. What I'm trying to achieve is store the posted value from sender into a variable in the receiverthen increment the variable it every time the sender posts. Then print the updated variable
This is what I have tried to do
$val= $_POST['val'];
$limit = 6 + $val;
echo $limit;
Im getting the result as 12. But what I want is
After first post result = 12
After second post result = 18
On and on...
NB:$_POST['val'] = 6;

Answer 1

session_start();
$limit = 6;
if(!isset($_SESSION['lastLimit'])) {
$_SESSION['lastLimit'] = 0;
}
if(!empty($_POST)) {
$_SESSION['lastLimit'] = $_SESSION['lastLimit'] + $limit;
$postedValue = $_POST['val'] + $_SESSION['lastLimit'];
echo $postedValue;
}

Answer 2

Because the web is stateless i.e. scripts do not remember anything that happened the last time a page/form was executed the receiver script does not remember anything from the last time it was run.
But dont panic, there is a way. Its called a SESSION and you can store data in the session which will then be available the next time this user connects to your site. In PHP you use it like this. The session is linked to this specific connection to a specific user.
receiver.php
<?php
// must be run at top of script, before any output is sent to the new form
session_start();
// did the form get posted and is the variable present
// or replace POST with GET if you are using an anchor to run the script
if ( $_SERVER['REQUEST_METHOD'] == 'POST' && isset($_POST['val']) {
if ( isset($_SESSION['limit'] ){
// increment the limit
$_SESSION['limit'] += (int)$_POST['val'];
} else {
// initialize the limit
$_SESSION['limit'] = (int)$_POST['val'];
}
echo 'Current value of limit is = ' $_SESSION['limit'];
} else {
// something is not right
// direct this user to some basic page like the homepage or a login
header('Location: index.php');
}

Answer 3

You need an intermediate layer to store the value.
Available options:
1) Global static value
2) session
3) file
4) database
I would recommend global value or session, as they data you want to store isn't that huge and would meet the requirements easily.
I would not write the syntax to store it in session as a number of people have already mentioned it. I just wanted to clarify the problem scenario and possible solutions.

Answer 4

You can store $limti into global varibale .
global $val;
$val += $_POST['val'];
$limit = 6 + $val;
echo $limit;