如何连续将用户输入数据推送到$ _SESSION数组然后检索它？

Question

I am trying to get my head around the way PHP sessions work. I am simply trying a hangman game where the first player inputs a secret word, a second player then starts to guess one letter at a time.

Let's says that the secret word is cat, player two tries, c then a then s. I would like the final output to be c a _.

  <?php
session_start();

global $word;
global $guess;
global $hangman;


if (isset($_POST['player1'], $_POST['word'])) {
    $_SESSION['word'] = $_POST['word'];
    $word = $_SESSION['word'];
}

if (isset($_POST['player2'], $_POST['guess'])) {
    $_SESSION['guess'] = $_POST['guess'];
    $guess = $_SESSION['guess'];
}

$counter = 0;
$word = strtolower($_SESSION['word']);
$guess = strtolower($_SESSION['guess']);
echo $word . "<br>";
$found = [];

$counter = 0;

for ($i = 0; $i < strlen($word); $i++) {
    if ($counter < strlen($word)) {
        if (strpos($word[$i], $guess) !== false) {
            $found[] = $guess;
            $counter++;
        } else {
            $found[] = " _ ";
        }
    }
}

  print_r($found);

Instead of printing out all the contents the found array, I am only getting one single letter to print every time. However, I would like to see the full concatenated string as I've mentioned above.

---

Here is what the output looks like:

Answer 1

How to continuously push user input data into $_SESSION array and then retrieve it?

An easy way to do that is by binding a variable with an element in the $_SESSION array. This is a useful trick that you won't find in the manual. A simple example:

$foo =& $_SESSION['foo'];

That assignment will bind $foo and $_SESSION['foo'] to the same value, so every update to $foo is also an update to $_SESSION['foo'].

Here is an example usage in the style of your hangman game:

<?php
session_start();

$word =& $_SESSION['word'];   //bind $word with $_SESSION['word']
$found =& $_SESSION['found']; //bind $found with $_SESSION['found']

if (isset($_REQUEST['word'])) {
    $word = str_split($_REQUEST['word']);
    $found = array_fill(0, count($word), '_');
}
if (isset($_REQUEST['guess'], $word, $found)) {
    $guess = array_fill(0, count($word), $_REQUEST['guess']);
    $found = array_replace($found, array_intersect($word, $guess));
}

echo join(' ', $found);

With the binding, the values of $word and $found will be saved as a part of the session data, without the need to do $_SESSION['word'] = $word; and $_SESSION['found'] = $found; anywhere in the script.

Note that I use $_REQUEST instead of $_POST to make it easier to test with a browser. Modify as desired.