Exercises: Array Filter - Javascript In Depth

Chapters:
00:00 Introduction
00:12 Warmup Exercise
04:55 Exercise 1
12:01 Exercise 2
15:57 Exercise 3
20:50 BONUS Exercise
30:40 Next Steps

[Psychox]

These videos aren’t getting enough views, the explanation is easy to understand with a great learning pace. You should be more popular:)

[OXIDE-isgs]

HiNader and everyone else, I solved the last exercise in one line :
let nums = [10, 20, 30, 40, 50].map((num) => num * 2).filter((num) => num > 50);
↑ this is because, for the arrow functions, if it can be written in one line, you do not need to use {} as well for return kw, it will return by default.
Awesome video, thanks! I worked individually on every exercise.

[nanlunglongtau]

I am liking and commenting on each video so that this channel can get more views as it rightly deerves

[JoeMilneEnglish]

Some people like sunsets, we like

const nums = [10, 20, 30, 40, 50]
.map((num) => {
return num * 2;
})
.filter((num) => {
if (num > 50) {
return true;
}
}
);

[akram]

1) Incase of filter - we have to explicitly return true or false in required cases.
2) we are not manipulating the elements of an array (as in case of array.map), we are trying to get rid off certain elements of an array.

[JoeMilneEnglish]

As I said in the practice array filter video, I learned the shorter code. So, for the bonus exercise I had:

const nums = [10, 20, 30, 40, 50];

const timesTwo = nums.map((num) => num * 2);

const over50 = timesTwo.filter((num) => num > 50);

console.log(nums);
// [10, 20, 30, 40, 50]

console.log(timesTwo);
// [20, 40, 60, 80, 100]

console.log(over50);
// [60, 80, 100]

My question is... is this bad practice? Is it better to make the code longer and therefore a bit more explicit (with return statements)? Or does it depend? Cheers, Nader!

[MauFerrusca]

Bonus answer, as short as I could:

const result =

[React_Media]

If possible could you do a video on the forEach method Array.

[issamchaaban]

const nums = [10, 20, 30, 40, 50]
.map((multiple) => multiple * 2)
.filter((overFifty) => (overFifty > 50 ? 1 : 0));
console.log(nums);

[comminatinmarkitingdealwit]

const nums = [10, 20, 30, 40, 50]
.map((num) => num * 2)
.filter((num) => num > 50);

this is my bunnies problem result. You told to us that this is not good for understanding purposes. If i write like this then i remove the extra 2 return statements right. By doing this the code become more efficient or same?

[KRAKENBACK..]

Hey nader, on exercise 2 I decided to challenge myself and see if I could make a function that would determine the sales tax if u gave it 2 inputs (tax and price) and then I used the function inside the lowPrices array. I just wanted to see if the way I set it up was good practice or if i should change anything.
const prices = [1.23, 19.99, 85.2, 32.87, 8, 5.2];

const taxedPrice = (tax, price) => {
decimalTax = tax / 100;
taxedTotal = decimalTax + price;
return taxedTotal;
};
console.log(taxedPrice(15, 1.23)); //seems good

const lowPrices = prices.filter((price) => {
if (taxedPrice(15, price) < 10) {
console.log(taxedPrice(15, price));
return true;
}
return false;
});
console.log(prices);
console.log(lowPrices);

[sheryianirfan]

This is my solution for no 3 i thing we dont need if statement here. const values = [[1, 2, 3], [0, 0, 1], [3, 6, 9], [0, 1, 2]];


const hasTwo = values.filter((two)=>{
return two.includes(2)
})
console.log(values)
console.log(hasTwo)

[bwyiocy]

Hi! My solution for prob 2 and bonus prob:

prob 2:

const prices = [1.23, 19.99, 85.2, 32.87, 8, 5.2];
const lowPrices = prices.filter(price=>{
let billAmt = price + (price*15)/100;
console.log(billAmt);
return billAmt < 10.00 ? true :false // used ternary operator
})
console.log(lowPrices);
console.log(prices);

bonus prob:

const over50 = nums.map((num)=>{
return num *2
}).filter((num)=>{
return num > 50 ? true : false // used ternary operator
})
console.log(over50);

[battleyt]

One-liners 😂
const numbers=[10, 20, 30, 40, 50]
const =>check>=50);
console.log(over50)

[sheryianirfan]

my solution for ex... 5
const nums = [10, 20, 30, 40, 50];

const timesTwo = nums.map((num)=>{
return num*2
})


const over50 = timesTwo.filter((val)=>{
if(val >= 50){
return true
}
})
console.log(nums)
console.log(timesTwo)
console.log(over50)