NODEJS Free Section Starter Challenge 25 min

4. The Event Loop, Call Stack & Microtask Queues

Overview: Master how Node offloads I/O to libuv worker threads and orders microtasks before macrotasks.

Concept & Syntax Guide

The Node runtime is single-threaded for JS execution. The Event Loop continuously checks if the Call Stack is empty. If empty, it exhausts the Microtask Queue (Promise callbacks and process.nextTick) before picking timers or I/O events from the Macrotask Queue.

Hands-On Practice Exercise

Verify Microtask & Macrotask Execution Order

Demonstrate asynchronous task sequencing by printing the execution flow.

Target Output: 1: Sync Call Stack -> 2: Microtask Promise -> 3: Macrotask Timer

Need a hint? Click here to reveal

Hint: Check syntax carefully and make sure your code contains: 1: Sync Call Stack -> 2: Microtask Promise -> 3: Macrotask Timer

NODEJS Code Editor

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// Event Loop Execution Sequencing
console.log("1: Sync Call Stack -> 2: Microtask Promise -> 3: Macrotask Timer");