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A collection of questions to test your understanding of JavaScript nuances and best practices.
Practice these questions and get feedbacks! It will help you improve your answer.
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1. What is the difference between a 'for...of' loop and a 'for...in' loop?
2. What is the purpose of the 'event loop' in JavaScript?
3. What is the purpose of the 'Symbol' primitive type?
4. What is the difference between == and ===?
5. What is the difference between a 'global' variable and a 'local' variable?
6. What is the purpose of the 'this' keyword?
7. What is the purpose of the 'hasOwnProperty()' method?
8. What is the difference between a 'shallow' and a 'deep' copy?
9. What is the difference between a 'promise' and a 'callback'?
10. What is the purpose of the 'Object.freeze()' method?
11. What is the difference between a 'static' and an 'instance' method?
12. What is the difference between '==' and '==='?
13. What is the difference between a 'function declaration' and a 'function expression'?
14. What is the purpose of the 'finally' block in a 'try...catch' statement?
15. What is the difference between a 'weak' and a 'strong' reference in JavaScript?
16. What is the purpose of the 'spread' operator (...)?
17. What is the purpose of the 'use strict' directive?
18. What is the purpose of the 'async/await' syntax?
19. What is the difference between let, const, and var?