diff --git a/Sprint-3/alarmclock/alarmclock.js b/Sprint-3/alarmclock/alarmclock.js
index 6ca81cd3b..06dea09dd 100644
--- a/Sprint-3/alarmclock/alarmclock.js
+++ b/Sprint-3/alarmclock/alarmclock.js
@@ -1,4 +1,84 @@
-function setAlarm() {}
+// Stores the interval ID so we can clear it later
+let interval = null;
+
+// Helper function: format seconds as mm:ss and update the display
+// This keeps the time-display logic in ONE place (CJ feedback: avoid repetition)
+function updateTimeDisplay(totalSeconds) {
+ const mins = String(Math.floor(totalSeconds / 60)).padStart(2, "0");
+ const secs = String(totalSeconds % 60).padStart(2, "0");
+ document.getElementById("timeRemaining").innerText =
+ "Time Remaining: " + mins + ":" + secs;
+}
+
+// Helper function: show or clear the feedback message in a separate element
+function showFeedback(message) {
+ document.getElementById("feedback").innerText = message;
+}
+
+function setAlarm() {
+ // Clear any previously running countdown
+ clearInterval(interval);
+
+ // Remove alarm style and clear feedback message
+ document.body.classList.toggle("alarm-activated", false);
+ showFeedback("");
+
+ // Stop any currently playing alarm sound before starting a new countdown
+ // (the user may not click "Stop" first before setting a new alarm)
+ pauseAlarm();
+
+ // Read the input value and convert it to a plain integer (total seconds)
+ let totalSeconds = parseInt(document.getElementById("alarmSet").value);
+
+ // Validate input: reject NaN, negative numbers, or empty field
+ if (isNaN(totalSeconds) || totalSeconds < 0) {
+ showFeedback("Please enter a valid number of seconds (0 or above).");
+ return;
+ }
+
+ // If input is 0, trigger the alarm immediately instead of waiting 1 second
+ if (totalSeconds === 0) {
+ updateTimeDisplay(0);
+ document.body.classList.toggle("alarm-activated", true);
+ playAlarm();
+ return;
+ }
+
+ // Display the initial time using the helper function
+ updateTimeDisplay(totalSeconds);
+
+ // Start the countdown: setInterval calls the callback every 1000 ms (1 second)
+ interval = setInterval(function () {
+ totalSeconds--; // subtract 1 second
+
+ if (totalSeconds <= 0) {
+ // Stop the interval when time runs out
+ clearInterval(interval);
+
+ updateTimeDisplay(0);
+
+ // Apply alarm style using a CSS class (separates presentation from logic)
+ document.body.classList.toggle("alarm-activated", true);
+
+ // Trigger the alarm sound (defined below the DO NOT EDIT line)
+ playAlarm();
+ return;
+ }
+
+ // Update the display with the new remaining time
+ updateTimeDisplay(totalSeconds);
+ }, 1000);
+}
+
+// Make the Stop button also stop the countdown (not just the sound)
+// Uses DOMContentLoaded so the button element exists before we attach the listener
+// This adds a SECOND listener without modifying the original code below
+document.addEventListener("DOMContentLoaded", function () {
+ document.getElementById("stop").addEventListener("click", function () {
+ clearInterval(interval);
+ document.body.classList.toggle("alarm-activated", false);
+ });
+});
// DO NOT EDIT BELOW HERE
diff --git a/Sprint-3/alarmclock/index.html b/Sprint-3/alarmclock/index.html
index 48e2e80d9..d2b886e5f 100644
--- a/Sprint-3/alarmclock/index.html
+++ b/Sprint-3/alarmclock/index.html
@@ -1,14 +1,15 @@
-
+
- Title here
+ Alarm clock app