JS2

j.js

// Task 1

const comparer = function (a, b){
  if(a > b) return 1;
  else if(a < b) return -1;
  else return 0;
}
console.log(comparer(1, 2));

// Task 2 factorial

const factorial = (() => {
  const cash = {};
  return function a(number) {
      if(number === 0) return 1;
      if(cash[number]) return cash[number];
      cash[number] = number * a(number - 1);
      return cash[number];
    };
})();

let factorial1 = factorial(100);


const factorial2 = (number) => {
  if(number === 0) return 1;
  else return number * factorial2(number - 1);
}
console.log(factorial2(1000));
// Task 3
function mergeNumbers(...numbers){
  return numbers.reduce((acc, cur, index) => {
    return acc + cur*Math.pow(10, numbers.length - index -1);
  }, 0);
}

console.log(mergeNumbers(9,8,7,7));

// Task 4

const square = (a, b = a) => a * b;
console.log(square(5, 10));

// Task 5
function absolutNumber(number){
  let dividers = [];
  for(let i = 0; i < number; i++){
    if(number % i === 0) dividers.push(i);
  }
  return dividers.reduce((acc, cur) => acc + cur, 0) === number;
}

console.log(absolutNumber(29));

// Task 14

const isSimpleNumber = (number) => {
  for(let i = 2; i < number; i++){
    if(number % i === 0) return false;
  }
  return true;
}