simple-cache-example.php

<?php

class API {
    public static function fetchUser($userID) {
        static $cache = [];

        $url = "https://example.com/users";
        $method = "GET";

        if (isset($cache[$url][$method][$userID])) {
            print "Using cached value";
            return $cache[$url][$method][$userID];
        }

        print "No cached value, fetching from API";
        $user = array("id" => $userID, "name" => "User $userID"); // Replace this with the actual API call

        $cache[$url][$method][$userID] = $user;

        return $user;
    }
}

$user1 = API::fetchUser(1);
print "\n" . json_encode($user1, JSON_PRETTY_PRINT) . "\n";

$user2 = API::fetchUser(2);
print "\n" . json_encode($user2, JSON_PRETTY_PRINT) . "\n";

$user1 = API::fetchUser(1);
print "\n" . json_encode($user1, JSON_PRETTY_PRINT) . "\n";

This is an example of a simple in-memory cache using a function-scoped static variable to prevent making duplicate API calls on the same request.

Output:

$ php simple-cache-example.php 
No cached value, fetching from API
{
    "id": 1,
    "name": "User 1"
}
No cached value, fetching from API
{
    "id": 2,
    "name": "User 2"
}
Using cached value
{
    "id": 1,
    "name": "User 1"
}