How can data be stored on a visitor's PC and then read in a PHP script?

To store data on a visitor's PC and then read it in a PHP script, you can use cookies or local storage. Cookies are small pieces of data stored on the visitor's browser, while local storage allows for larger amounts of data to be stored locally. You can set a cookie or store data in local storage using JavaScript on the client-side, and then access that data in your PHP script when the page is loaded. 

// Setting a cookie with PHP
setcookie("username", "JohnDoe", time() + 3600, "/"); // expires in 1 hour

// Accessing the cookie in PHP
if(isset($_COOKIE["username"])) {
    $username = $_COOKIE["username"];
    echo "Welcome back, $username!";
} else {
    echo "Welcome, guest!";
}

Keywords

cookies local storage session variables PHP file handling data persistence

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