sandrabosk

PTWD-MIA-OCT2019/MAY2020

sandrabosk

Source

sandrabosk

// 1: Calculate the total population in the given array (`data`):

const data = [
  {
    country: 'USA',
    pop: 340
  },
  {
    country: 'France',
    pop: 133

sandrabosk

• 10-javascript-array-methods-you-should-know
• https://www.ibrahima-ndaw.com/blog/15-must-known-javascript-array-methods-in-2020/
• How to Remove Array Duplicates in ES6
• Basic Javascript: Removing Duplicates from an Array
• additional - map, filter, reduce exercises
• coursework.vschool.io

sandrabosk

Challenge 1:

Given an array of numbers, filter out the numbers that are not even, and are less than 100.

const numbers = [1, 60, 112, 123, 100, 99, 73];

const newArray = numbers.filter(number => {
  return number % 2 === 1 && number < 100;
});

sandrabosk

// **********************************************************************
// 1: Sort an array from shortest string to the longest.
// **********************************************************************

const arrOfStrings = ['cat', 'wolf', 'yo', 'animal'];

const sortedByLength = [...arrOfStrings].sort((a, b) => {
  return a.length - b.length
});

sandrabosk

// ************************************************************************************
// https://www.codewars.com/kata/array-dot-diff/train/javascript
// Your goal in this kata is to implement a difference function, which subtracts one list from another and returns the result.
// It should remove all values from list a, which are present in list b.
// array_diff([1,2],[1]) == [2]
// If a value is present in b, all of its occurrences must be removed from the other:
// array_diff([1,2,2,2,3],[2]) == [1,3]
// ************************************************************************************

sandrabosk

// ************************************************************************************
// https://www.codewars.com/kata/53da3dbb4a5168369a0000fe/train/javascript
// Create a function (or write a script in Shell) that takes an integer as an argument 
// and returns "Even" for even numbers or "Odd" for odd numbers.
// ************************************************************************************


function even_or_odd(number) {
  if (number % 2 === 0) {
    return `Even`;

sandrabosk

// ************************************************************************************
// https://www.codewars.com/kata/century-from-year/javascript
// The first century spans from the year 1 up to and including the year 100,
// the second - from the year 101 up to and including the year 200, etc.

// Task :
// Given a year, return the century it is in.
// Input , Output Examples ::
// centuryFromYear(1705)  returns (18)
// centuryFromYear(1900)  returns (19)

sandrabosk

// ************************************************************
// 1: Reverse the array
// ************************************************************

const numbers = [3, 5, 6, 2];

const reversed = numbers.slice().reverse();

console.log(reversed); // => [ 2, 6, 5, 3 ]
console.log(numbers); // => [ 3, 5, 6, 2 ]