mini-proj/count-down-timer.html

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Countdown Timer</title>
  </head>
  <body>
    <!-- 
        Create a countdown timer that starts from a specified number of seconds and updates every second.
         Display an alert when the countdown reaches zero.
     -->
    <button onclick="startTimer()">Start Countdown</button>

    <script>
      function startTimer() {
        let seconds = parseInt(
          prompt("Enter the countdown duration in seconds:")
        );

        if (isNaN(seconds) || seconds <= 0) {
          alert("Invalid input. Please enter a positive number.");
          return;
        }

        const timer = setInterval(function () {
          console.log(seconds);
          if (seconds === 0) {
            clearInterval(timer);
            alert("Countdown reached zero!");
          } else {
            seconds--;
          }
        }, 1000);
      }
    </script>
  </body>
</html>