HackerRank.com — 10 Days of JavaScript — Solutions

Here is my solutions of HackerRank — 10 Days of JavaScript Practice problem ,.

Note : I’m just attaching the solutions part only

Hence Day 0 is nothing hard that’s why I’m Not writing for Day 0

Day 1: Arithmetic Operators

Problem : https://www.hackerrank.com/challenges/js10-arithmetic-operators/problem

Solutions :

function getArea(length, width) {
  let area;
   // Write your code here
  area = length * width;
  return area;
}

Day 1: Functions

Problem : https://www.hackerrank.com/challenges/js10-function/problem

Solutions :

function factorial(n) {
  let res = 1;
  for(let i = 2; i<=n; i++) {
    res *= i;
  }
  return res;
}

Day 1: Let and Const

Problem : https://www.hackerrank.com/challenges/js10-let-and-const/problem

Solution :

let r = readLine();
const PI = Math.PI;
console.log(PI * (r**2));
console.log(2 * (PI*r));

Day 2: Conditional Statements: If-Else

Problem : https://www.hackerrank.com/challenges/js10-if-else/problem

Solution :

function getGrade(score) {
  let grade;
  if(score > 25 && score <=30){
    grade = 'A'
  }else if(score > 20 && score <=25){
    grade = 'B'
  }else if(score > 15 && score <= 20) {
    grade = 'C'
  }else if(score > 10 && score <=15){ 
    grade = 'D'
  }else if(score > 5 && score <=15){
    grade = 'E'
  }else if(score >=0 && score <= 5) {
    grade = 'F'
  }
  return grade;
}

Day 2: Conditional Statements: Switch

Problem : https://www.hackerrank.com/challenges/js10-switch/problem

Solutions :

function getLetter(s) {
  let letter;
 // Write your code here
  switch(true) {
    case 'aeiou'.includes(s[0]):
      letter = 'A';
    break;
   case 'bcdfg'.includes(s[0]):
     letter = 'B';
   break;
   case 'hjklm'.includes(s[0]):
     letter = 'C';
   break;
   case 'npqrstvwxyz'.includes(s[0]):
     letter = 'D';
    break;
  }
  return letter;
}

Day 2: Loops

Problem : https://www.hackerrank.com/challenges/js10-loops/problem

Solutions :

function vowelsAndConsonants(s) {
  for(let i=0; i<s.length; i++) {
    let c = s[i]
    if(c==='a' || c==='e' || c==='i' || c==='o' || c==='u'){
      console.log(c)
     }
  }
  for(let i=0; i<s.length; i++) {
    let c = s[i]
    if(c !== 'a' && c!=='e' && c!=='i' && c!=='o' && c!=='u') {    
       console.log(c)
    }
  }
}

Day 3: Arrays

Problem : https://www.hackerrank.com/challenges/js10-arrays/problem

Solutions :

function getSecondLargest(nums) {
  let max1 = 0;
  for (const e of nums) {
    if (max1 < e) {
      max1 = e;
    }
  }
  let max2 = 0;
 
  for (const e of nums) {
    if (max2 < e && e < max1) {
       max2 = e;
    }
  }
  return max2;
}

Day 3: Try, Catch, and Finally

Problem : https://www.hackerrank.com/challenges/js10-try-catch-and-finally/problem

Solutions :

function reverseString(s) {
  try {
    s = s.split('').reverse().join('');
  }catch(e) {
     console.log(e.message);
  }finally {
    console.log(s);
  }
}

Day 3: Throw

Problem : https://www.hackerrank.com/challenges/js10-throw/problem

Solution :

function isPositive(a) {
  if(a > 0){
     return 'YES'
  }else if(a===0){
     throw new Error("Zero Error")
  }else{
     throw new Error("Negative Error")
  }
}

Day 4: Count Objects

Problem : https://www.hackerrank.com/challenges/js10-count-objects/problem

Solutions :

function getCount(objects) {
   return objects.filter(ob => ob.x === ob.y).length
}

Day 4: Classes

Problem :

Solution: https://www.hackerrank.com/challenges/js10-class/problem

class Polygon{
  constructor(arr){
    this.sides = arr;
  }
  perimeter(){
    return this.sides.reduce((acc,crr) =>  acc = acc + crr , 0)
  }
}

Day 5: Inheritance

Problem : https://www.hackerrank.com/challenges/js10-inheritance/problem

Solutions :

Rectangle.prototype.area = function() {
   return this.w * this.h
}
class Square extends Rectangle{
  constructor(s){
     super(s, s);
     this.w = s;
     this.h = s;
  }
}

Day 5: Template Literals

Problem : https://www.hackerrank.com/challenges/js10-template-literals/problem

Solutions :

function sides(literals, ...expressions) {
    const [a, p] = expressions;
    let s1 = (p + Math.sqrt(p**2 -16 *a))/4;
    let s2 = (p - Math.sqrt(p**2 -16 *a))/4;
    return [s1, s2].sort();
}

Day 5: Arrow Functions

Problem : https://www.hackerrank.com/challenges/js10-arrows/problem

Solution :

function modifyArray(nums) {
    return nums.map(num => num % 2 === 0 ? num*2 : num*3);
}

Day 6: Bitwise Operators

Problem : https://www.hackerrank.com/challenges/js10-bitwise/problem

Solution :

function getMaxLessThanK(n, k) {
    let max_anb = 0;
    for (let b = n; b > 0; b--) {
        for (let a = b-1; a > 0; a--) {
            if ((a & b) < k && (a & b) > max_anb){
                max_anb = (a&b);
            }
        }
    }
    return max_anb;
}

Day 7: Regular Expressions I

Problem : https://www.hackerrank.com/challenges/js10-regexp-1/problem

Solution :

function regexVar() {

   let re = /^([aeiou]).+\1$/;
   return re;
}

More are Coming ….