diff --git a/src/examples/js/concurrent.js b/src/examples/js/concurrent.js
index 3eed0d2..4e11c32 100644
--- a/src/examples/js/concurrent.js
+++ b/src/examples/js/concurrent.js
@@ -16,18 +16,19 @@ const processTask = async (todo, batchId) => {
 const executeConcurrent = async (todos, maxBatchSize) => {
 	console.log(`\ndo <= ${maxBatchSize} of ${todos.length} tasks (concurrently), at any given time\n`);
 	const done = [];
-	const todosCopy = todos.slice();
+
 	const worker = async (_, batchIndex) => {
-		let todo = todosCopy.shift();
-		while (todo) {
+		let todo = todos.shift();
+		while (todo !== undefined) {
 			const [result] = await Promise.allSettled([processTask(todo, batchIndex + 1)]);
 			done.push(result);
-			todo = todosCopy.shift();
+			todo = todos.shift();
 		}
 	};
 
-	const batchStarters = Array.from({length: maxBatchSize}, worker);
-	await Promise.all(batchStarters);
+	const batches = Array.from({length: maxBatchSize}, worker);
+	await Promise.allSettled(batches);
+
 	return done;
 };
 
diff --git a/src/examples/js/without-lib.js b/src/examples/js/without-lib.js
index 5f7de65..f2f033c 100644
--- a/src/examples/js/without-lib.js
+++ b/src/examples/js/without-lib.js
@@ -13,7 +13,6 @@ const processTask = async (todo, batchId) => {
 	return out;
 };
 
-// Everywhere start/end is used is repititive and error prone
 const executeWithoutLibrary = async (todos, maxBatchSize) => {
 	console.log(`\ndo <= ${maxBatchSize} of ${todos.length} tasks, at any given time (no library)`);
 	const done = [];