joefearnley

const maxMultiple = (divisor, bound) => {
    let result = divisor;
    
    for (let i = divisor; i <= bound; i *= divisor) {
        result = i;
    }

    return result;
}

joefearnley

const largestNumber = num => {
    result = '';

    for(let i = 1; i <= num; i++) {
        result += '9';
    }

    return parseInt(result);
};

joefearnley

const firstDigit = str => str.split('').filter(s =>!isNaN(s))[0];

describe('firstDigit()', () => {
    it('return the first digit in a string', () => {
        // arrange
        const str = "var_1__Int2";
        
        // act
        const result = firstDigit(str);

joefearnley

// basic with for loop
const factorialNumber = num => {
    let result = 1;

    for(let i = result + 1; i <= num; i++) {
        result *= i;
    }

    return result;
};

joefearnley

const encloseInBrackets = str => `(${str})`;

describe('encloseInBrackets()', () => {
    it('adds () around a string', () => {
        // arrange
        const str = "Yo";
        
        // act
        const result = encloseInBrackets(str);

joefearnley

const caseInsensitivePalindrome = str => str.toLowerCase() === str.split('').reverse().join('').toLowerCase();


describe('caseInsensitivePalindrome()', () => {
    it('returns true for a case insensitive palindrome', () => {
        // arrange
        const str = 'AaBaa';
        
        // act
        const result = caseInsensitivePalindrome(str);

joefearnley

const arrayReplace = (array, elemToReplace, substitutionElem) => array.map((el, i) => el === elemToReplace ? substitutionElem : el);

describe('arrayReplace()', () => {
    it('adds a border around entire application', () => {
        // arrange
        const array = [1, 2, 1];
        const elemToReplace = 1;
        const substitutionElem = 3;
        
        // act

joefearnley

const alternatingSums = weights => [
    weights.filter((weight, i) => i % 2 === 0).reduce((a, c) => a + c),
    weights.filter((weight, i) => i % 2 !== 0).reduce((a, c) => a + c)
];


describe('alternatingSums()', () => {
    it('returns alternating sums of even and odd', () => {
        // arrange
        const nums = [50, 60, 60, 45, 70];

joefearnley

const allLongestStrings = array => {
    let longestLength = array[0].length;
    array.forEach(s => {
        longestLength = s.length > longestLength ? s.length : longestLength;
    });
    
    return array.filter(s => s.length === longestLength);
}

/**

joefearnley

const add = (...nums) => nums.reduce((a, c) => a + c);

describe('add()', () => {
    it('adds two numbers', () => {
        // arrange
        const num1 = 1;
        const num2 = 2;
        
        // act
        const result = add(num1, num2);