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ProblemWe are required to write a JavaScript function that takes in a number n. Our function should return an array of all such number pairs that when summed are n and both of them are prime.ExampleFollowing is the code − Live Democonst num = 26; const isPrime = (n) => { if (n % 2 === 0) return false; let sqrtn = Math.sqrt(n)+1; for (let i=3; i < sqrtn; i+=2) { if (n % i === 0) return false; } return true; } const primeList = (a) => { if (isPrime(a)) return ... Read More
ProblemWe are required to write a JavaScript function that takes in a string of characters, str, and a single character, char.Our function should construct a new string that contains the immediate next character present in str after each instance of char (if any).ExampleFollowing is the code − Live Democonst str = 'this is a string'; const letter = 'i'; const findNextString = (str = '', letter = '') => { let res = ''; for(let i = 0; i < str.length; i++){ const el = str[i]; const next = str[i + 1]; if(letter === el && next){ res += next; }; }; return res; }; console.log(findNextString(str, letter));Outputssn
ProblemWe are required to write a JavaScript function that takes in an array of numbers. Our function should try and remove the least number of elements from the array so that the array becomes an increasing sequence.ExampleFollowing is the code − Live Democonst arr = [1, 100, 2, 3, 100, 4, 5]; const findIncreasingArray = (arr = []) => { const copy = arr.slice(); for(let i = 0; i < copy.length; i++){ const el = arr[i]; const next = arr[i + 1]; if(el > next){ copy[i] = undefined; }; }; return copy.filter(Boolean); }; console.log(findIncreasingArray(arr));Output[ 1, 2, 3, 4, 5 ]
ProblemWe are required to write a JavaScript function that takes in a number n. Starting with ‘1’ our function should construct a string of length n that contains ‘1’ and ‘0’ alternatingly.ExampleFollowing is the code − Live Democonst num = 12; const buildString = (num = 1) => { let res = ''; for(let i = 0; i < num; i++){ if(i % 2 === 0){ res += 1; }else{ res += 0; }; }; return res; }; console.log(buildString(num));Output101010101010
ProblemWe are required to write a JavaScript function that takes in a decimal number, converts it into binary and reverses its 1 bit to 0 and 0 to 1 and returns the decimal equivalent of new binary thus formed.ExampleFollowing is the code − Live Democonst num = 45657; const reverseBitsAndConvert = (num = 1) => { const binary = num.toString(2); let newBinary = ''; for(let i = 0; i < binary.length; i++){ const bit = binary[i]; newBinary += bit === '1' ? '0' : 1; }; const decimal = parseInt(newBinary, 2); return decimal; }; console.log(reverseBitsAndConvert(num));Output19878
ProblemWe are required to write a JavaScript function that takes in a number n and returns the sum of all perfect cube numbers smaller than or equal to n.ExampleFollowing is the code − Live Democonst num = 23546; const sumPerfectCubes = (num = 1) => { let i = 1; let sum = 0; while(i * i * i
Increasing TriangleFor the purpose of this problem, suppose an increasing triangle to be like this − 1 2 3 4 5 6 7 8 9 10ProblemWe are required to write a JavaScript function that takes in a number n and returns the sum of numbers present in the nth row of increasing triangle.ExampleFollowing is the code − Live Democonst num = 15; const rowSum = (num = 1) => { const arr = []; const fillarray = () => { let num = 0; for(let i = 1; i a + b, 0); }; console.log(rowSum(num));Output1695
ProblemWe are required to write a JavaScript function that takes in string containing digits and our function should return true if the sum of even digits is greater than that of odd digits, false otherwise.ExampleFollowing is the code − Live Democonst num = '645457345'; const isEvenGreater = (str = '') => { let evenSum = 0; let oddSum = 0; for(let i = 0; i < str.length; i++){ const el = +str[i]; if(el % 2 === 0){ evenSum += el; }else{ oddSum += el; }; }; return evenSum > oddSum; }; console.log(isEvenGreater(num));Outputfalse
ProblemSuppose a school organises this game on their Annual Day celebration −There are ”n” water taps and “n” students are chosen at random. The instructor asks the first student to go to every tap and open it. Then he has the second student go to every second tap and close it. The third goes to every third tap and, if it is closed, he opens it, and if it is open, he closes it. The fourth student does this to every fourth tap, and so on. After the process is completed with the "n"th student, how many taps are open?We ... Read More
ProblemWe are required to write a JavaScript function that takes in a string. Our function should construct a new string in which all the consonants should hold their relative position and all the vowels should be pushed to the end of string.ExampleFollowing is the code − Live Democonst str = 'sample string'; const moveVowels = (str = '') => { const vowels = 'aeiou'; let front = ''; let rear = ''; for(let i = 0; i < str.length; i++){ const el = str[i]; if(vowels.includes(el)){ rear += el; }else{ front += el; }; }; return front + rear; }; console.log(moveVowels(str));Outputsmpl strngaei