JS - Cardio Simple Cool Problems from Traversy Media

cardio.js

// Anagram Check
const anagram = (str1, str2) => helper(str1) === helper(str2);
const helper = (str) => str.toLowerCase().split('').sort().join('');

console.log('Anagram: ', anagram('Dormitory', 'DirtyRoom'));


const getChunkArray = (arr, len) => {
  const chunkArray = [];
  let i = 0;
  while (i < arr.length) {
    chunkArray.push(arr.slice(i, i + len));
    i = i + len;
  }
  return chunkArray;
};
console.log('Chunked Array: ', getChunkArray([1, 2, 3, 4, 5, 6, 7], 5));

const flattenArray = (chunkedArrays) => {
  //return chunkedArray.reduce((a, b) => a.concat(b));
  // return [].concat.apply([], chunkedArrays)
  return [].concat(...chunkedArrays);
};
console.log('Flatten Array ', flattenArray([ [ 1, 2 ], [ 3, 4 ], [ 5, 6 ], [ 7 ] ]));


const longestWord = (sentence) => {
  const wordArr = sentence.toLowerCase().match(/[a-z0-9]+/g);

  const sortedArr = wordArr.sort((a, b) => b.length - a.length);

  const longestWordArr = sortedArr.filter((word) => word.length >= sortedArr[0].length );

  if (longestWordArr.length > 1) {
    return longestWordArr;
  } else {
    return longestWordArr[0];
  }
};

console.log('Longest Word: ', longestWord('Hello there, How are you doing ?'));


const letterChanges = (str) => {
  let newStr = str.toLowerCase().replace(/[a-z]/gi, char => {
    if (char === 'z' || char === 'Z') {
      return 'a';
    } else {
      return String.fromCharCode(char.charCodeAt() + 1);
    }
  });

  newStr = newStr.replace(/a|e|i|o|i/gi, vowel => vowel.toUpperCase());

  return newStr;
}

console.log('Letter and Vowel capitalization: ', letterChanges('Hello There'));


const reverseString = (str) => {
  return str
          .split('')
          .reverse()
          .join('');
  // let newStr = '';
  // for (i = 0; i < str.length; i++) {
  //   newStr = str[i] + newStr;
  // }
  // return newStr;
}
console.log('Reverse String ', reverseString('olleH World'));


const isPalindrome = (str) => str.toLowerCase() === str.toLowerCase().split('').reverse().join('')
console.log('Palindrome: ', isPalindrome('Malayalam'));


const reverseInt = (number) => {
  const reverse = number.toString().split('').reverse().join('');
  return parseInt(reverse) * Math.sign(number);
}
console.log('Reverse Int: ', reverseInt(-105));


const capitalizeFirstLetters = (str) => {
  // return newStr = str.replace(/\b[a-z]/gi, (char) => char.toUpperCase());
  const strArr = str.toLowerCase().split(' ');
  for(let i = 0; i < strArr.length; i = i + 1) {
    strArr[i] = strArr[i].substring(0, 1).toUpperCase() + strArr[i].substring(1);
  }
  return strArr.join(' ');
}
console.log('Capitalize First letters: ', capitalizeFirstLetters('js love yo'));


const maxCharacter = (str) => {
  const characterMap = {};
  for (const c of str) {
    if (!characterMap[c]) {
      characterMap[c] = 1;
    } else {
      characterMap[c]++;
    }
  }

  let maxNum = 0;
  let maxChar = '';
  for (let key in characterMap) {
    if (characterMap[key] > maxNum) {
      maxNum = characterMap[key];
      maxChar = key;
    }
  }
  return maxChar;
}
console.log('Max Character: ', maxCharacter('BananaTerracottaPie'));


// console.log('FizzBuzz: ', fizzBuzz());
function fizzBuzz() {
  for (let i = 1; i <= 100; i++) {
    if (i % 15 === 0) {
      console.log('FizzBuzz');
    } else if (i % 5 === 0) {
      console.log('Buzz');
    } if (i % 3 === 0) {
      console.log('Fizz');
    } else {
      console.log(i);
    }
  }
  return 'Done';
}

// CHALLENGE 1: ADD ALL NUMBERS
// Return a sum of all parameters entered regardless of the amount of numbers - NO ARRAYS
// ex. addAll(2,5,6,7) === 20

// Solution 1: ES5 arguments & for loop
function addAll() {
  var args = Array.prototype.slice.call(arguments);
  var total = 0;
  for (let i = 0; i < args.length; i++) {
    total += args[i];
  }
  return total;
}

// Solution 2: ...rest & reduce/forEach
function addAll(...numbers) {
  return numbers.reduce((acc, cur) => acc + cur);
}

// CHALLENGE 2: SUM ALL PRIMES
// Pass in a number to loop up to and add all of the prime numbers. A prime number is a whole number greater than 1 whose only factors are 1 and itself
// ex. sumAllPrimes(10) == 17

function sumAllPrimes(num) {
  let total = 0;

  function checkForPrime(i) {
    for (let j = 2; j < i; j++) {
      if (i % j === 0) {
        return false;
      }
    }
    return true;
  }

  for (let i = 2; i <= num; i++) {
    if (checkForPrime(i)) {
      total += i;
    }
  }
  return total;
}

// CHALLENGE 3: SEEK & DESTROY
// Remove from the array whatever is in the following arguments. Return the leftover values in an array
// ex. seekAndDestroy([2, 3, 4, 6, 6, 'hello'], 2, 6) == [3, 4, 'hello']

// Solution 1: arguments, indexOf, filter
function seekAndDestroy(arr) {
  const args = Array.from(arguments);

  function filterArr(arr) {
    // Return true if NOT in array
    return args.indexOf(arr) === -1;
  }

  return arr.filter(filterArr);
}

// Solution 2: ...rest, filter & includes
function seekAndDestroy(arr, ...rest) {
  return arr.filter(val => !rest.includes(val));
}

// CHALLENGE 4: SORT BY HEIGHT
// Some people are standing in a row in a park. There are trees between them which cannot be moved. Your task is to rearrange the people by their heights in a non-descending order without moving the trees.
// ex.
// a = [-1, 150, 190, 170, -1, -1, 160, 180]
// sortByHeight(a) == [-1, 150, 160, 170, -1, -1, 180, 190]

function sortByHeight(a) {
  const arr1 = [];
  const arr2 = [];

  a.forEach((val, i) => (val === -1 ? arr1.push(i) : arr2.push(val)));

  const sortArr = arr2.sort((a, b) => a - b);

  arr1.forEach((val, i) => sortArr.splice(arr1[i], 0, -1));

  return sortArr;
}

// CHALLENGE 5: MISSING LETTERS
// Find the missing letter in the passed letter range and return it. If all letters are present, return undefined
// ex.
// missingLetters("abce") == "d"
// missingLetters("abcdefghjklmno") == "i"
// missingLetters("abcdefghijklmnopqrstuvwxyz") == undefined

function missingLetters(str) {
  let compare = str.charCodeAt(0);
  let missing;

  str.split('').map((char, i) => {
    if (str.charCodeAt(i) == compare) {
      ++compare;
    } else {
      missing = String.fromCharCode(compare);
    }
  });

  return missing;
}

// CHALLENGE 6: EVEN & ODD SUMS
// Take in an array and return an array of the sums of even and odd numbers
// ex.
// evenOddSums([50, 60, 60, 45, 71]) == [170, 116]

function evenOddSums(arr) {
  let evenSum = 0;
  let oddSum = 0;

  arr.forEach(num => (num % 2 === 0 ? (evenSum += num) : (oddSum += num)));

  return [evenSum, oddSum];
}