Add counter snippet

snippets/counter.md

@@ -0,0 +1,27 @@
+### counter
+
+Creates a counter with the specified range, step and duration for the specified selector.
+
+Check if `step` has the proper sign and change it accordingly.
+Use `setInterval()` in combination with `Math.abs()` and `Math.floor()` to calculate the time between each new text draw.
+Use `document.querySelector().innerHTML` to update the value of the selected element.
+Omit the fourth parameter, `step`, to use a default step of `1`.
+Omit the fifth parameter, `duration`, to use a default duration of `2000`ms.
+
+```js
+const counter = (selector, start, end, step = 1, duration = 2000) => {
+	let current = start,
+		_step = (end - start) * step < 0 ? -step : step,
+		timer = setInterval(() => {
+			current += _step;
+			document.querySelector(selector).innerHTML = current;
+			if (current >= end) document.querySelector(selector).innerHTML = end;
+			if (current >= end) clearInterval(timer);
+		}, Math.abs(Math.floor(duration / (end - start))));
+	return timer;
+};
+```
+
+```js
+counter('#my-id', 1, 1000, 5, 2000); // Creates a 2-second timer for the element with id="my-id"
+```