Word Mapping

<!--Write a PHP program WordMapper.php that takes a text from a textarea and prints each word
and the number of times it occurs in the text. The search should be case-insensitive.
The result should be printed as an HTML table.-->

<!DOCTYPE html>
<html>
<head lang="en">
    <meta charset="UTF-8">
    <title>Word Mapping</title>
    <style type="text/css">
        table, td {
            background-color: #eee;
            border: 1px solid #000;
        }
    </style>
</head>
<body>
<form method="post">
    <textarea name="text" cols="60" rows="5" placeholder="Enter your text..."></textarea>

    <p><input type="submit" value="Count words"/></p>
</form>
<table>
    <tbody>
    <?php
    if (!isset($_POST) || !isset($_POST['text']) || trim($_POST['text']) === '') {
        die("The Input Form can't been Empty!!!");
    }

    $text = strtolower(trim($_POST['text']));
    $words = str_word_count($text, 1);
    $resultMap = array();
    foreach ($words as $word) {
        if (!array_key_exists($word, $resultMap)) {
            $resultMap[$word] = 1;
        } else {
            $resultMap[$word] += 1;
        }
    }

    foreach ($resultMap as $key => $number):?>
        <tr>
            <td><?= $key ?></td>
            <td><?= $number ?></td>
        </tr>
    <?php endforeach; ?>
    </tbody>
</table>
</body>
</html>