Implement alarm functionality with countdown and validation

Alex-Os-Dev-Lab · Alex-Os-Dev-Lab · commit 1d5456c38cec · 2026-03-14T18:02:49.000Z
diff --git a/Sprint-3/alarmclock/alarmclock.js b/Sprint-3/alarmclock/alarmclock.js
@@ -1,4 +1,38 @@
-function setAlarm() {}
+timerInterval = null;
+function setAlarm() {
+  // 1. Get the input from the user
+  const inputField = document.getElementById("alarmSet");
+  let timeRemaining = parseInt(inputField.value);
+
+  // 2. Validate: If no number or 0 is entered, do nothing
+  if (isNaN(timeRemaining) || timeRemaining <= 0) {
+    return;
+  }
+
+  // 3. Clear any existing timer; prevent multiple alarms running at once
+  clearInterval(timerInterval);
+
+  // 4. Update the display immediately
+  updateTimeDisplay(timeRemaining);
+
+  // 5. Start the countdown
+  timerInterval = setInterval(() => {
+    timeRemaining -= 1;
+
+    updateTimeDisplay(timeRemaining);
+
+    // 6. Check if timer hit zero
+    if (timeRemaining <= 0) {
+      clearInterval(timerInterval);
+      playAlarm();
+      document.body.style.backgroundColor = "red";
+    }
+  }, 1000);
+}
+
+// mm:ss formatting
+
+//00:00 format
 
 // DO NOT EDIT BELOW HERE
 
diff --git a/Sprint-3/alarmclock/index.html b/Sprint-3/alarmclock/index.html
@@ -4,7 +4,7 @@
     <meta charset="utf-8" />
     <meta name="viewport" content="width=device-width, initial-scale=1.0" />
     <link rel="stylesheet" href="style.css" />
-    <title>Title here</title>
+    <title>Alarm clock app</title>
   </head>
   <body>
     <div class="centre">
