Instant Cookie Setting in PHP

To make a set cookie appear immediately in the $_COOKIE array, you can use a clever technique. The essence of the technique is as follows: first, set the cookie using setcookie, and then manually write it into the $_COOKIE array:

php<?php
  setcookie('str', 'eee');
  $_COOKIE['str'] = 'eee';
  
  var_dump($_COOKIE['str']); // will immediately output 'eee'
?>

To prevent the cookie from being sent to the browser every time, you can place the cookie setting inside a condition. If the cookie doesn't exist, then set it:

php<?php
  if (!isset($_COOKIE['str'])) { // if the cookie doesn't exist
    setcookie('str', 'eee');
    $_COOKIE['str'] = 'eee';
  }
  
  echo $_COOKIE['str']; // will output 'eee'
?>

Let's discuss how this works. On the first visit to the page, we will enter the if block, set the cookie in the browser, and immediately write it into $_COOKIE. Then, echo will output the value we manually wrote.

On subsequent visits to the page, we will not enter the if block, but $_COOKIE will contain our cookie, which has already come from the browser. Thus, both on the first visit and on subsequent ones, our cookie will be present in $_COOKIE.