niklasramo

const pipe = (...fns) => fns.reduce((f, g) => (...args) => g(f(...args)));
const compose =  (...fns) => fns.reduce((f, g) => (...args) => f(g(...args)));

// Example
const addFoo = str => str + 'foo';
const addBar = str => str + 'bar';
const addFoobar = pipe(addFoo, addBar);
const addBarfoo = compose(addFoo, addBar);
addFoobar('hello ') // hello foobar
addBarfoo('hello ') // hello barfoo

niklasramo

function lotto(amountOfNumbers, from, to) {
  const numbers = [];
  for (let i = 0; i < amountOfNumbers; i++) {
    let number = null;
    while (number === null || numbers.indexOf(number) > -1) {
      number = Math.floor(Math.random() * (to - from + 1)) + from;
    }
    numbers.push(number);
  }
  return numbers.sort((a, b) => a - b);