Must Know Javascript Interview Questions

MORE Junior Javascript Interview questions! Since my last JavaScript Interview video got lots of feedback and engagement I thought I'd make a followup. These interview questions are tailored for junior software, frontend and fullstack web developers. Like last time, I've included suggested answers for each question.

[max_iddqd]

The main difference between regular and arrow functions is a context (this): regular function changes context (this = parent object), arrow function don't (this stays the same). This can be very useful.

[wotizit]

THIS:

The handling of this is also different in arrow functions compared to regular functions.

In short, with arrow functions there are no binding of this.

In regular functions the this keyword represented the object that called the function, which could be the window, the document, a button or whatever.

With arrow functions the this keyword always represents the object that defined the arrow function.

[Brandon-tzpn]

04:39 I cant believe I've been coding for this long and never noticed this. I guess I automatically write my return statements the right way without thinking about it.

[peanutcelery]

One big one for arrow functions is the this reference.

[KAZVorpal]

THE MAIN difference for arrow functions is that they don't have the synonym "this".
That should be mentioned by anyone facing that question.

[incarnateTheGreat]

Thanks for these.

I'd say the gotcha function call with the line break might be disregarded nowadays with Prettier and autoformatters, but still good to mention.

[jadehendricks]

One thing though is that promises are taken to the micro task queue which takes precedence over the callstack. While SetTimeouts etc do not.

[min]

This really helps, thanks for the video!

[AIShorts]

great video. your explainations are crystal clear and concise. more interview questions please. thanks.

[crforever]

Today is my very first interview day and this video already helped me a lot. Thank you! I just subscribed and I'll keep track of your videos

[js]

You’re awesome thank you for sharing your experience 😊

[Rantalytics]

awesome, thank you Catherine, this was awesome

[Adam-qeyo]

Woo hoo! I knew most of the answers. Except the last questions #4.

[geesunjang]

This is so helpful Catherine. Thanks for the video! :)

[swtlynn]

Could you do an example on what happens during a live coding assessment or a whiteboard session? I know this is part of the technical interview and I have NO clue what the heck happens in them.

[carloanimationTV]

very informative I also noticed your nice hair

[norkrze]

The example with object returning is mindfulness test)

[daniel]

la penúltima pregunta, acerca de la diferencia entre foo1() y foo2() ¿se debe al salto de línea según entendí?

[Drag_Star]

Amazing explanation Thank you sooo much

[vycos-zen]

at 2:30 it is actually not correct i think. this function for example

const test = () => {return "hi"};

and run it in your browser console. than run test(); it works. the reason why CODE SEMPLE 3 does not work because the Car class has to be defined. like

class Car {constructor(){
this.color = () => "hi"
}}

than you can instantiate it with

const test = new Test();

and can be called by

test.greet();

so i would look into clarifying that part, at around 2:30. And by the way, great video over all, sorry for the nit picking. Good content and using it for refreshing for an interview. thank you.