 <!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="UTF-8" />
  <title>Random Number Picker</title>
  <style>
    body {
      font-family: Arial, sans-serif;
      text-align: center;
      margin: 20px;
    }
    button {
      padding: 10px 20px;
      font-size: 16px;
      margin-top: 20px;
      cursor: pointer;
    }
    .output {
      margin-top: 20px;
    }
    .warning {
      color: red;
      font-weight: bold;
    }
  </style>
</head>
<body>
  <h1>Random Number Picker</h1>

  <!-- ปุ่มกดเรียกฟังก์ชัน generateNumbers() -->
  <button onclick="generateNumbers()">Generate Numbers</button>

  <div class="output">
    <p id="generated-numbers"><strong>Generated Numbers:</strong> None</p>
    <p id="remaining-numbers"><strong>Remaining Numbers:</strong> None</p>
    <p id="warning-msg" class="warning"></p>
  </div>

  <script>
    // 1) สร้างอาร์เรย์ [1..75]
    let remainingNumbers = [];
    for (let i = 1; i <= 75; i++) {
      remainingNumbers.push(i);
    }

    // 2) เก็บเลขที่สุ่มได้
    let generatedNumbers = [];

    // 3) ฟังก์ชันสุ่มเลขทีละ 3
    function generateNumbers() {
      // หากน้อยกว่า 3 ให้โชว์ข้อความเตือนในหน้าเว็บ แทนการ alert
      if (remainingNumbers.length < 3) {
        document.getElementById("warning-msg").textContent = 
          "Not enough numbers left to generate 3 unique numbers.";
        return;
      } else {
        // เคลียร์ข้อความเตือนหากเคยมี
        document.getElementById("warning-msg").textContent = "";
      }

      // สุ่ม 3 หมายเลข
      for (let i = 0; i < 3; i++) {
        const randomIndex = Math.floor(Math.random() * remainingNumbers.length);
        const number = remainingNumbers.splice(randomIndex, 1)[0];
        generatedNumbers.push(number);
      }
      // อัปเดตผล
      updateDisplay();
    }

    // 4) แสดงผลบนหน้าเว็บ
    function updateDisplay() {
      const genEl = document.getElementById('generated-numbers');
      const remEl = document.getElementById('remaining-numbers');

      // แสดงเลขที่สุ่มมาแล้ว
      if (generatedNumbers.length > 0) {
        genEl.innerHTML = `<strong>Generated Numbers:</strong> ${generatedNumbers.join(', ')}`;
      } else {
        genEl.innerHTML = `<strong>Generated Numbers:</strong> None`;
      }

      // แสดงเลขที่ยังเหลือ
      if (remainingNumbers.length > 0) {
        remEl.innerHTML = `<strong>Remaining Numbers:</strong> ${remainingNumbers.join(', ')}`;
      } else {
        remEl.innerHTML = `<strong>Remaining Numbers:</strong> None`;
      }
    }

    // เรียกอัปเดตแสดงครั้งแรก
    updateDisplay();
  </script>
</body>
</html>

created 3 months ago by สรวิศ กิ่งโก้

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