Array drills

Make list drill

function makeList(item1, item2, item3) {
  const arr = [item1, item2, item3];
  return arr;
}


Add to list drill

function addToList(list, item) {
  list.push(item);
  return list;
}


Access first and third items

function accessFirstItem(array) {
  return (array[0]);
}

function accessThirdItem(array) {
  return (array[2]);
}


Array length and access

function findLength(array) {
  return (array.length);
}

function accessLastItem(array) {
  return array.pop();
}


Array copying I

function firstFourItems(array) {
  return array.slice(0, 4);
}

function lastThreeItems(array) {
  return array.slice(-3);
}


Array copying II

function minusLastItem(array) {
  const lengthMinusOne = array.length - 1
  return array.slice(0, lengthMinusOne)
}

function copyFirstHalf(array) {
  const halfArray = (array.length / 2)
  return array.slice(0, halfArray)
}


Squares with map

function squares(array) {
  function squared(num) {
    return (num ** 2);
  }
  return array.map(squared);
}


Sort greatest to least

function greatestToLeast(array) {
 function sortGreatest(a, b){
   return b-a;
 } return array.sort(sortGreatest);
}


Filter

function shortWords(array) {
  function lessThanFive(num) {
    return num.length < 5;
  } return array.filter(lessThanFive)
}


Find

function divisibleBy5(array) {
  function divisible(num) {
    return num % 5 === 0;
  } return array.find(divisible);
}