A few days ago, I connected with a senior software engineer, who is also a bootcamp grad. He was kind enough to offer mock interviews with recent bootcamp grads from LinkedIn. The questions he asked were commonly seen in his interviews and his peers.
Questions and Answers
1. What are some primitive data types?
2. what is the difference between
null is an assigned value and
undefined means a variable has been declared but no value.
Note: I wrote a blog about
undefined a while ago with the bonus section of new ES2021 feature, go check it out if interested!
3. what is the difference between
On top of the answer above,
undeclared means a variable has been declared without the
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4. There are multiple ways to declare a variable, can you tell me them?
5. What is the difference between
var: globally scoped; can be reassigned, redeclared, updated; will get
let: locally (function/block) scoped, cannot be reassigned and redeclared, but can be updated; will get
Reference Errorwith “hoisting”
const: locally (function/block) scoped, cannot be reassigned, redeclared and updated; will get
Reference Errorwith “hoisting”
I also wrote a blog discussing the difference between all three of those. Feel free to check it out if interested!
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6. Can you describe what “hoisting” means?
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7. What is a callback function?
A callback function is a function passed into another function as an argument, which is then invoked inside the outer function to complete some kind of routine or action. (MDN)
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8. What are some ways of handling asynchronous behavior?
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9. What is the difference between
==: checks for value equality and performs type coercion (i.e. converts the types of the variables to match each other) before checking the values.
=== : does not perform type coercion; evaluate whether the variables being compared have both the same value AND the same type
3 == "3" // true
3 === "3" // false
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10. What is the “DOM”?
The Document Object Model (DOM) is a programming interface for HTML and XML documents. It represents the page so that programs can change the document structure, style, and content. The DOM represents the document as nodes and objects (MDN).
11. What are a few ways you can grab an HTML element from the DOM?
- Gets ID:
- Gets Class:
- Gets Tag:
- Gets Selector (Single):
- Gets Selector (all):
12. What is the return structure of a
This returns a static (not live) NodeList representing a list of the documents’ elements that match a specified group of selectors (MDN).
Certainly, there were a few questions that completely caught me off guard. However, the mock interviewer was really patient with me and explained everything to me. I highly recommend to do at least 1 or 2 mock interviews with your peers, or someone you know who is willing to help! Good luck with your interviews!!
Also, in case you haven’t noticed those emojis, I hope you will be able to guess what movies they represent along the way — and yes they are all Pixar movies:
- 🏁 + 🚗 + ⛽️ = Cars
- 🐀 + 🍅 + 🧑🍳 = Ratatouille
- 💪 + 💥 + 👓 = The Incredibles
- 📖 + 🤠 + 🧑🚀 = Toy Story
- 🔎 + 🐠 + 🦭 = Finding Dory
- 🚪 + 😱 + 💡 = Monster Inc.
That’s all I got today and thank you for being a wonderful reader!