Senior JavaScript Technical Interview Question | Learn Web Development Now

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[kamalbennani]

If you want to push your code little bit further you may wanna use async/await feature as well.
```
/*
1. Implement ES6 into the 'john' {}
2. Return value from the 'deduct' () after 2s
*/


const sleep = time => new Promise((resolve) => setTimeout(resolve, time))


var john = {
name: 'John Doe',
balance: 1500,
async deduct(amount) {
await sleep(2000);
this.balance = this.balance - amount;
return '${this.name} has a balance of ${this.balance}';
}
}




```

[kimnejudne]

Thanks for the video! I was actually able to solve the problem in my head without looking at the fiddle or looking at any reference. This means I can probably pass senior dev interviews by now. This video helped my confidence. Thanks.

[bezrodnovAleksey]

It's a normal practice to start with easy stuff like zhe one in this video - just to understand who you are dealing with. One of the real questions I was asked for senior position after simple ones was - implement promise polyfil xD And I was very close, just not enough time to finish it properly (I had just 30 minutes). Try it out (without googling) it's a lot of fun!

[AbouHallassi]

Awesome interview problem, as a beginner it's unblock my 'this' keyword problem. Finally I understand very well the concept of this and arrow function utility . Thanks for your video and hope you've many like that

[suryatejapothureddy]

8:02 mins is all you need to understand the best parts of ES6.

[soykike]

For the second one If I'm correct you can also save 'this' into a local variable inside that scope that way it will be available for the settimeout function, correct me if I'm wrong I don't have a console to test right now

[justadev____]

You didn't really explain why you used the Promise and how it solved the problem.

[Christopher_]

Wouldn't the ES6 way of doing this be using a Class instead?

[kevin]

If this are the type of interview questions they ask i might be able to work in sillicon valley too, damn

[shubhsagar]

Awesome man, very helpful... Promises are really important :)

[kamalbennani]

`this` doesn't reference the scope of the function, but it does reference the parent of the object (which is in this case the Window) (You can verify it by console logging this)

[aaron___]

Was this considered senior-level at the time? These seem like everyday methods and solves.

[xcoolplayz]

Hmmmm, it seems the explanation of the last challenge is not true, setTimeout put the execution to call stack but not change its context

[chidinwaka]

Thank you for sharing Jade. I'm wondering if you got the job you interviewed for. Please let us know.

[imfluder]

I would also convert john into a class

class John {
constructor() {
this.name = 'John Doe';
this.balance = 1500;
}

deduct(amount) {
return new Promise((resolve, reject) => {
this.balance = this.balance - amount;
setTimeout(() => {
resolve(`${this.name} has a balance of ${this.balance}`);
}, 2000)
});
}

}

(async function() {
const johns = new John();
document.body.innerText = await johns.deduct(300);
})();

[arunkaiser]

Hi i can't get one thing what promise exactly doing here?

[aqua]

how is this senior developer interview ? it's just syntax testing?

[alexkakhnovskyi]

I don't believe that was the question for a Senior level position

[stas]

I guess the task is too easy for senior position

[wescorman]

I'm filing an abuse report for your keyboard..