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Modern JavaScript (ES6+)
Question 1
Which keyword is used to export a function from a module in ES6?
- A
module.exports
- B
export
- C
exports
- D
define
Question 2
What does the Promise.allSettled() method return?
- A
Resolves if all promises are fulfilled
- B
Rejects if any promise is rejected
- C
Returns an array with the results of all promises, regardless of their status
- D
Cancels unresolved promises
Question 3
What is the result of the following code?
const obj = { a: 1, b: 2 };
const { a, b } = obj;
console.log(a, b);
- A
{ a: 1, b: 2 }
- B
1 2
- C
undefined undefined
- D
Error
Question 4
What does the Symbol type represent in JavaScript?
- A
A unique, immutable primitive value
- B
A reference to an object
- C
A deprecated data type
- D
A special property of arrays
Question 5
Which syntax allows combining multiple arrays into one?
- A
Array.prototype.concat()
- B
Spread operator (...)
- C
Both a and b
- D
Rest operator (...)
Question 6
What is the purpose of optional chaining (?.)?
- A
Prevents accessing properties on null or undefined objects
- B
Accesses private properties
- C
Automatically assigns default values
- D
Handles circular references
Question 7
Which feature allows embedding variables inside strings?
- A
String interpolation (#)
- B
Template literals (````)
- C
Spread operator (...)
- D
String concatenation
Question 8
What does the rest operator (...) do?
- A
Combines multiple arrays into one
- B
Collects remaining elements into an array or object
- C
Spreads an array into individual elements
- D
Executes asynchronous code
Question 9
What is the output of the following code?
const arr = [1, 2, 3];
const result = [...arr, 4, 5];
console.log(result);
- A
[1, 2, 3, 4, 5]
- B
[[1, 2, 3], 4, 5]
- C
[4, 5, 1, 2, 3]
- D
Error
Question 10
What is the purpose of Promise.any()?
- A
Resolves when all promises are fulfilled
- B
Resolves when the first promise is fulfilled
- C
Resolves or rejects based on the fastest promise
- D
Resolves when the first promise is fulfilled or rejects when all promises fail
There are 10 questions to complete.