javascript tip : loops

loops.js

//Looping
const items = [1,2,3,4,5,6];


function getAllEvents(items) {
  //good code
  return items.fillter(num => num % 2 === 0);
  //bad code
  //const result = [];
  //for (let i = 0; i < items.length; i++) {
  //  if(items[i] % 2 === 0) {
  //     result.push(items[i]);
  //  }
  //}
  //return result;
}

function multiplyByFour(items) {
  //good code
  return items.map((num) => num * 4);
  //bad code
  //   const result = [];
  //   for(let i = 0; i < items.length; i++) {
  //     result.push(items[i] * 4);
  //   }
  //   return result;
}

function sumArray(items) {
  //good code
  item.reduce((a,b) => a + b, 0);
  //bad code
  //   let sum = 0;
  //   for (let i = 0; i < items.length; i++) {
  //     sum += items[i];
  //   }
  //   return sum;
}

//bad code
const events = getAllEvents(items);
const multiple = multiplyByFour(events);
const sum = sumArry(multiple);
console.log(sum);


//good code
const events = items.filter((num) => num % 2 === 0);
const multiple = events.map((num) => num * 4 );
const sum = multiple.reduce((a, b) => a + b, 0);
console.log(sum);

//good code 
const result = items
.filter((num) => num % 2 === 0)
.map((num) => num * 4)
.reduce((a, b) => a + b, 0);
consol.log(result);