What is the difference between passing data from a popup to an existing page in PHP and JavaScript?

When passing data from a popup to an existing page in PHP, you can use sessions or cookies to store the data temporarily and then access it on the existing page. In JavaScript, you can use window.opener to access the parent window and pass data using postMessage or localStorage. 

// Popup page
session_start();
$_SESSION['data'] = "Hello from popup";

// Existing page
session_start();
if(isset($_SESSION['data'])){
    $data = $_SESSION['data'];
    echo $data;
}

Keywords

PHP JavaScript data passing popup existing page

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