JavaScript Coding Exercises For Beginners: Beginner Exercises Part 5

This is the last in the 'beginners' exercises series that takes you through another 5 problems to solve with JavaScript.

[kremowydzien]

for excercise 2 I used regex to check the matches:

const check = (str) => str.split("")
.filter(el => /[aeiou]/.test(el)).length

[yassineel]

I am learning js for more than 8 month and I still can't lose those exercices and this is only for beginners, I have only watched tutorials and didn't practice it by myself, I feel really depressed.

[Elator]

Oh, this is what I was looking for! Javascript challenges for beginners! Thanks for your work man!

[davidsaso]

for exercise 1, you don't need to pass the comparing function to sort, you only need it for comparing numbers. So you could have put this instead:

and would have worked just fine.

[ognjenpopovic]

Exercise 3 - I hope this is the simplest solution
function convertCoins(amount, coins = [25, 10, 5, 2, 1]) {
let totalCoins = [];
let j = 0;

while (amount > 0) {
if (amount >= coins[j]) {
amount -= coins[j];
totalCoins.push(coins[j]);
}

if (amount < coins[j]) {
j++;
}
}
return totalCoins;
}

[xc]

2:03 this also works
function a(str) {
return str.split('').sort().join('')
}
a("paper")

[kremowydzien]

Exercise 4. My solution is not that elegant but it works. I used a for loop and the array method includes:


const check = (str => {
const newArr = [];
const arr = str.split("");
for (let i = 0; i < arr.length; i++) {
if (!newArr.includes(arr[i])) {
newArr.push(arr[i]);
}
}
return newArr;
})

[alpinestylecom]

// Exercise 5
firstNotRepeatedChar = str => {
return str
.split('')
.filter((value, index, array) => array.indexOf(value) ===
}

[tekqist]

Did something very similar for #2:

const vowels = 'aouie'
const vowelCount = (str) => str.split('').filter(x => (vowels.split('')).indexOf(x) > -1).length;


// 2

Also your videos are dope!
Thank you so much!

[hersheynaik]

My solution for the vowels exercise 2:
const vowels = (str) => str.match(/[aeiou]/g).length;

[saifeddine]

Exercise 3 - I used for and while loop combined with each other... :
function countCoins(money){
let coins = [25, 10, 5, 2, 1];
let result = [];
for (let i=0; i<coins.length; i++) {
while(money>=coins[i]){

= money-coins[i];
}
}
return result
}

[monotoneguy]

Thank you so much, just subbed ! Btw are you planning on making another series for intermediate level?

[sandoxs]

For exercise #2 it would be easier to do it this way:


}

[triptichhetri]

my solution to #2:
const vowelCount = (str, vowel = ['a', 'e', 'i', 'o', 'u']) => vowel.filter(x => str.indexOf(x) != -1).length;
I didn't split the string and it still worked.

[huynhkequang]

Hi JDC,

The last exercise will return multiple values if the string has more than one unique values. For example, adbcacbdef will have expected output = e, f. I think we need to extract the first index of the final array, Or change the first filter to find.

[fahdekarim]

if you mind : your last exercice, about first no reapeted character, your function return all not repeated character instead of the first character only !
i did some test and : i found that the first 'Filter' must be Find. Please check that

[GauravDeb]

write-a javascript code to display a table of palindrome numbers between 100 and 500 through an html document.
Sir can you show how to do this program

[Ismael-jhbx]

Hello, this was my solution to exercise 2


function countVowels(str){
str.split('')
let count = 0
for(let i = 0; i < str.length; i++){
if(str[i]=="a" || str[i]=="e" ||str[i]=="i" || str[i]=="o" || str[i]== "u"){
count++
}
}
return count;
}
4
3
*** Yes I know it's long, but it worked**

[vitaliiparaskiv]

ex.II (a little different)
const countVowels = (str) =>
str.split('').filter(x => 'aeiou'.includes(x)).length

[anarjafarov]

This one is simpler: const strOrder = str => str.split ('').sort ().join ('')