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  <meta charset="utf-8">
  <title>JS Alphabet Pattern 29 - Try It</title>
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  <h1>Full symmetric square (E..A..E)</h1>
  <p>Edit <code>top</code> or <code>j &gt; i</code>, then click Run.</p>

  <pre id="output"></pre>

  <script>
    (() => {
      const A = "A".charCodeAt(0);
      const top = "E".charCodeAt(0);

      function row(i) {
        let line = "";
        for (let j = top; j >= A; j--) line += (j > i ? String.fromCharCode(j) : String.fromCharCode(i)) + " ";
        for (let j = A + 1; j <= top; j++) line += (j > i ? String.fromCharCode(j) : String.fromCharCode(i)) + " ";
        return line.trimEnd();
      }

      let result = "";
      for (let i = top; i >= A; i--) result += row(i) + "\n";
      for (let i = A + 1; i <= top; i++) result += row(i) + "\n";

      document.getElementById("output").textContent = result;
    })();
  </script>
</body>
</html>

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JavaScript Alphabet Pattern 29 (Try It)