Question

我是PHP的新手。对于课堂作业，我们需要制作一个Tic Tac Toe游戏。到目前为止，这是我的代码：

<html>
<body>
<h1>Tic Tac Toe</h1>

<form method="POST" action="<?php echo $_SERVER['PHP_SELF']; ?>">
    <input type="text" name="input">
    <input type="submit" name="submit">
</form>

<?php
//Display Determinations

//Top Left
if (!ISSET($_POST['submit'])) {
    $GLOBALS['ul_truefalse'] = true;
    $GLOBALS['turn'] = 1;
    $this_happened = "!isset";
}
if (ISSET($_POST['submit'])) {
    $GLOBALS['turn'] = $GLOBALS['turn'] + 1;
    if ($GLOBALS['turn'] == 3) {
        $GLOBALS['turn'] = 1;
    }
}
if ($GLOBALS['ul_truefalse'] == true) {
    $GLOBALS['ul_display'] = "UL";
    if (ISSET($_POST['input']) and $_POST['input'] == "ul" and $GLOBALS['turn'] == 1) {
        $GLOBALS['ul_display'] = "X";
        $GLOBALS['ul_truefalse'] = false;
        $this_happened = "p1 ul";
    }
    if (ISSET($_POST['input']) and $_POST['input'] == "ul" and $GLOBALS['turn'] == 2) {
        $GLOBALS['ul_display'] = "O";
        $GLOBALS['ul_truefalse'] = false;
    }
}

echo "Player " . $GLOBALS['turn'] . ", it's your turn!";
echo $this_happened;
?>


<table border="1" width="40%">
    <tr>
        <td><?php echo $GLOBALS['ul_display'] ?></td>
        <td></td>
        <td></td>
    </tr>   
    <tr>
        <td></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
    </tr>
</table>



</body>
</html>

这是输出（左侧是页面加载时，右侧是玩家1进入＆＃34; ul＆＃34;）：http://i.imgur.com/G0JaXYY.png

问题是当if (!ISSET($_POST['submit'])) {变为false时，if语句中定义的字符串会丢失其值，从而导致未定义的变量错误。我尝试将它们存储在隐藏的表格框中，但它并没有解决问题。我将我的代码发送给论坛上的一个人，他说它有效。为什么会这样？我该如何解决这个问题？

Answer 1

试试这个：

<html>
<body>
<h1>Tic Tac Toe</h1>

<form method="POST" action="<?php echo $_SERVER['PHP_SELF']; ?>">
    <input type="text" name="input">
    <input type="submit" name="submit">
</form>

<?php
if(!session_id())
    session_start();

//Display Determinations

//Top Left
if (!ISSET($_POST['submit'])) {
    $_SESSION['ul_truefalse'] = true;
    $_SESSION['turn'] = 1;
    $this_happened = "!isset";
}
if (ISSET($_POST['submit'])) {
    $_SESSION['turn'] = $_SESSION['turn'] + 1;
    if ($_SESSION['turn'] == 3) {
        $_SESSION['turn'] = 1;
    }
}
if ($_SESSION['ul_truefalse'] == true) {
    $_SESSION['ul_display'] = "UL";
    if (ISSET($_POST['input']) and $_POST['input'] == "ul" and $_SESSION['turn'] == 1) {
        $_SESSION['ul_display'] = "X";
        $_SESSION['ul_truefalse'] = false;
        $this_happened = "p1 ul";
    }
    if (ISSET($_POST['input']) and $_POST['input'] == "ul" and $_SESSION['turn'] == 2) {
        $_SESSION['ul_display'] = "O";
        $_SESSION['ul_truefalse'] = false;
    }
}

echo "Player " . $_SESSION['turn'] . ", it's your turn!";
echo $this_happened;
?>


<table border="1" width="40%">
    <tr>
        <td><?php echo $_SESSION['ul_display'] ?></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
    </tr>
    <tr>
        <td></td>
        <td></td>
        <td></td>
    </tr>
</table>



</body>
</html>

PHP $ GLOBALS失去价值

1 个答案: