Add functionality

Author: tajulafreen

Source-Code/StopWatch/script.js

@@ -0,0 +1,49 @@
+let milliseconds = 0;
+let seconds = 0;
+let minutes = 0;
+let timer;
+
+const startButton = document.getElementById("start");
+const stopButton = document.getElementById("stop");
+const resetButton = document.getElementById("reset");
+
+const updateTime = () => {
+  milliseconds += 1;
+  if (milliseconds === 100) {
+    milliseconds = 0;
+    seconds += 1;
+  }
+  if (seconds === 60) {
+    seconds = 0;
+    minutes += 1;
+  }
+  document.getElementById("milliseconds").innerText =
+    milliseconds < 10 ? `0${milliseconds}` : milliseconds;
+  document.getElementById("seconds").innerText =
+    seconds < 10 ? `0${seconds}` : seconds;
+  document.getElementById("minutes").innerText =
+    minutes < 10 ? `0${minutes}` : minutes;
+};
+
+const startTimer = () => {
+  clearInterval(timer);
+  timer = setInterval(updateTime, 10);
+};
+
+const stopTimer = () => {
+  clearInterval(timer);
+};
+
+const resetTimer = () => {
+  clearInterval(timer);
+  milliseconds = 0;
+  seconds = 0;
+  minutes = 0;
+  document.getElementById("milliseconds").innerText = "00";
+  document.getElementById("seconds").innerText = "00";
+  document.getElementById("minutes").innerText = "00";
+};
+
+startButton.addEventListener("click", startTimer);
+stopButton.addEventListener("click", stopTimer);
+resetButton.addEventListener("click", resetTimer);