Interview Concepts Event Loop Microtask vs Macrotask Deep vs Shallow Copy Memory Leak
Continue your JavaScript Tutorial learning path with hands-on explanation, code practice, and quiz.
Course
JavaScript Tutorial
Estimated Time
8 min
Progress
55%
Track Position
40 / 73
Lesson Overview
Simple Explanation
Event loop async tasks schedule karta hai. Promise callbacks microtask queue me aur setTimeout macrotask queue me jata hai. Shallow copy nested references share karta hai; deep copy independent structure banata hai. Memory leak tab hota hai jab unused references release nahi hoti.
Code Explanation
Promise log setTimeout se pehle run hota hai kyun ke microtask priority high hoti hai.
Output Description
Execution order se queue behavior samajh aayega.
Practice Exercise
Ek object ka shallow aur deep copy banao aur nested mutation compare karo.
Extra Explanation
Why This Matters
Interview Concepts Event Loop Microtask vs Macrotask Deep vs Shallow Copy Memory Leak is core to dynamic behavior. Strong fundamentals here help you build forms, API flows, and interactive UI with confidence.
Real-World Workflow
Complex features are usually split into small functions, then verified through focused logging and tiny test cases.
Common Mistakes to Avoid
Avoid uncontrolled globals, weak error handling, and ignored async states. Define clear input-output expectations for each function.
Example + Live Practice
<script>
console.log("A");
setTimeout(() => console.log("Macrotask timeout"), 0);
Promise.resolve().then(() => console.log("Microtask promise"));
const original = { user: { name: "Ali" } };
const shallow = { ...original };
const deep = JSON.parse(JSON.stringify(original));
shallow.user.name = "Changed by shallow";
console.log("Original after shallow:", original.user.name);
deep.user.name = "Changed by deep";
console.log("Original after deep:", original.user.name);
console.log("B");
</script>Try It Yourself
Test Your Knowledge
Quiz Coming Soon
Quiz for this lesson is not added yet.
Save Your Work
Lesson ke end par apna code save karein. Dashboard me aap kabhi bhi is saved code ko dobara dekh sakte hain.