Javascript Question & Answer Practice

Javascript Practice – Questions & Answers

Beginner Level

Q16. JavaScript data types.

String, Number, Boolean, Object, Undefined, Null

Q17. Create a string variable.

let name = "Vijay";

Q18. Create an array.

let arr = [1,2,3];

Q19. Access array element.

arr[0];

Q20. Create an object.

let user = { name:"Vijay", age:25 };

Q21. setInterval example.

setInterval(()=>{
  console.log("Run");
},1000);

Q22. Array push.

arr.push(4);

Q23. Array pop.

arr.pop();

Q24. Map function.

arr.map(x => x*2);

Q25. Filter function.

arr.filter(x => x > 2);

Q26. Try catch.

try{
  risky();
}catch(e){
  console.log(e);
}

Q27. Hoisting.

Variables/functions moved to top during execution.

Q28. Call stack.

Tracks function execution order.

Q29. Event bubbling.

Event propagates from child to parent.

Q30. Event delegation.

Handling events using parent element.