Passing variable between pages in PHP

Receive form data explicitly

Use $_POST for POST form data and $_GET for query-string data. Check whether a value exists, validate it for its intended use, and escape it when inserting it into HTML.

$name = trim($_POST['name'] ?? '');
if ($name === '') {
echo 'Name is required.';
} else {
    echo 'Hello ' . htmlspecialchars($name, ENT_QUOTES, 'UTF-8');
}

This is the recommended starting pattern. The detailed examples below are retained for explanation, comparison and related variations.

We often have to pass values of variables between pages in our site. These are required in many different ways. Some time we collect some value from a database and want to retain the value for the particular user throughout the site as the user moves between pages. There are different ways for passing such values of the variables. It can be passed within a site or even outside the site. We will discuss some of the ways with their possible uses.

Passing variable with data to different pages

Passing variable values between pages using session

This is one of the secured ways the variables are passed between pages. The best example of such a system is when we see our user-id inside a member area after we logged in. In a member login system the user details are verified and once found correct, a new session is created and with user id of the member and this value is stored at server end. Every time a new page is opened by the browser, the server checks the associated session value and display the user id. This system is more secure and the member doesn't get any chance to change the values. For more details on session variables & its management read this.

Passing variables between pages using cookies

Cookies are stored at the user or the client end and values can be passed between pages using PHP. But here the client browser can reject accepting cookies by changing the security settings of the browser. So this system can fail to pass values between pages if user or client end settings are changed. But cookies are quit useful in handling user entered values and passing them between pages. Read more details on handling cookies in PHP

Passing variables between pages using URL

We can pass variable values between pages through the URL ( in address bar of the browser). Here values are visible to the user and others as they appear in the address bar and also in the browser history. This is not a secure way to transfer sensitive data like password, etc. Read more on how to pass variables between pages using URL.

Web Forms

Forms are used mainly to collect data and then transfer them to a processing page. Here the processing page uses one of the above methods to pass values to different pages as per the requirements. Forms can be used to pass values to different sites. Forms can submit the data to a processing script running at a different URL in different server.

These are some of the way of transferring data variables between pages. There is no clear rule to use a particular method to pass the variables between pages. Here are some standard way of doing with reasons. All variables needs sanitization before using when they arrive from external sources.

Uses	Method	Reason
Login form with Userid and password	POST	Id and password should not be visible in query string
Sending Product id	GET	The url can be bookmarked for future uses.
Feedback form	Post	Several data can be posted
Favorite buying pattern of User	Cookies	Data stored in user computer
User Login status	Session	Secured data is maintained at server end

Passing data from PHP to JavaScript

JavaScript runs at client side , where PHP runs at server end. We can pass data from PHP to JavaScript by sending the data to client end.

<?php
$php_variable = "hello world"; // Declaring PHP variable 
echo "<script>var js_variable = \"$php_variable\";</script>"; // Passing to JavaScript variable
?>
<script>
document.write(js_variable); // JavaScript output  
</script>

Declaring variables Transfer variables between pages and between sites Cookies to store Infomation

Subhendu Mohapatra

Author & Instructor at plus2net

I write and maintain practical tutorials on Python, PHP, SQL, JavaScript, HTML, jQuery, and web development at plus2net. The tutorials focus on clear explanations, working examples, and code that readers can test and adapt while learning.

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shakil	04-02-2010
I want , How to pass Javascript variable value to PHP Variable

smo	04-02-2010
Without reloading the page we can't pass JavaScript variable to PHP script. We can use Ajax to do that.

Alieu	19-11-2010
I want a script that will allow me to pass values in php variables on to a different form

Roshan	10-05-2011
I just want to play the variable between php and javascript.

Harsh karwal	04-09-2012
hi, i am a fresher in PHP and trying to learn it. i need a code for display data on another page when some one submit his details like his name, his mbl no., his age etc.. in a form and after click on submit button the same data is display.

Mano	27-04-2013
i have fill the value in textbox when click the button value are pass to new screen .How to pass the value?

smo123	29-04-2013
You can pass data from child window to parent window and same way you can try by reversing.

Rohit	01-10-2009
thanks a lot for such good material of php.

Different ways of passing variables with data between pages