ancyrweb

const elements = [1, 2, 3, 4];
const appendedElements = [...elements, 5]; // [1, 2, 3, 4, 5]
const prependedElements = [0, ...appendedElements]; // [0, 1, 2, 3, 4, 5]

ancyrweb

const elements = [1, 2, 3, 4, 5];

// remove last element
const lastElementRemoved = elements.slice(0, 4); // [1, 2, 3, 4]

// remove first element
const firstElementRemoved = elements.slice(1); // [2, 3, 4, 5]

// remove first and last element (chaining)
const firstAndLastElementRemoved = elements.slice(0, 4).slice(1) // [2, 3, 4]

ancyrweb

const elements = [1, 2, 3, 4, 5];
const indexToRemove = 2; // starts from 0, so it targets the third element
const nextElements = [
  ...elements.slice(0, indexToRemove), 
  ...elements.slice(indexToRemove + 1)
]; // [1, 2, 4, 5]

ancyrweb

const users = [
  {
    name: "Jane",
    balance: 100.00
  },
  {
    name: "John",
    balance: 55.25
  }
];

ancyrweb

const users = [
  {
    name: "Jane",
    balance: 100,
  },
  {
    name: "John",
    balance: 75,
  },
  {

ancyrweb

const users = [
  {
    name: "Jane",
    balance: 100,
  },
  {
    name: "John",
    balance: 75,
  },
  {

ancyrweb

const elements = [1, 2, 3, 1, 4, 5, 2, 6, 6];
const isUnique = (value, index, array) => array.indexOf(value) === index;
const nextElements = elements.filter(isUnique); // [1, 2, 3, 4, 5, 6]

ancyrweb

const elements = [1, 2, 3, 4, 5];
const nextElements = elements.reduce(
  (previousValue, currentValue) => previousValue + currentValue,
  0
); // 15

ancyrweb

const elements = [1, 2, 3, 4, 5];
const sum = (a, b) => a + b;

const nextElements = elements.reduce(sum, 0); // 15

ancyrweb

const users = [
  {
    name: "Jane",
    balance: 100,
  },
  {
    name: "John",
    balance: 75,
  },
  {