Programming exercise #13 - get only unique items from array of objects

Programming exercise #11 - Clone object, without copying reference

// So, you have object like this

const obj = {

firstName: "John",

lastName: "Doe"

}

//Please create second object, that have firstName and lastName
// properties from first object.

console.log(myClonedObject) // {firstName: "John", lastName: "Doe"}

// Your goal is copy only properties, not the reference to object.
// so when we change first object like this :

obj.firstName = "Mary"

// output on cloned object should look the same.

console.log(myClonedObject) // {firstName: "John", lastName: "Doe"}

// Please post your answer as codepen, jsbin or link into your github gist.

Programming exercise #10 - emit 6 values in interval, remember about reseting

// Interesting exercise, that I have found in StackOverflow

// After click in button, return values from 0 to 6 with interval 1000 ms.

// After every click in button, again start emitting from 0 to 6

// I suggest you, to use rxjs

Programming exercise #9 - one array from two

// Simple exercise for today

// Your goal is to merge two arrays into one.

const arr1 = ["a", "b", "c"];

const arr2 = ["e", "f", "g"];

// expected result ["a", "b", "c", "e", "f", "g"]

Programming exercise #8 - dealing with objects

Imagine, that you have array of objects like this:

const array = [

{ name: "something", value: "something" },

{ name: "somethingElse", value: "something else" },

{ drinkName: "vodka", value: "Pshenicnaja" }

];

I want to ask you, about transform this array into one object, that looks like this:

const res = { name: 'somethingElse',
  value: 'Pshenicnaja',
  drinkName: 'vodka' }

As you can see, we do not want get duplicated keys in result.

Programming exercise #7 - promises basics

Very simple exercise - please create a promise, that returns some text after 2 seconds. When there was an error, console.error message.
Also do the same, using async and await syntax.

Programming exercise #6 - start emitting value, when all items emits something [rxjs]

So, new RXJS exercise:
Create two buttons like this:
const button1 = document.querySelector('#btn1');
const button2 = document.querySelector('#btn2');

After click on every button emit some value, but start doing this only, when user click both first and second button. When this rule is satisfied, emit last value.

Programming exercise #5 - Merge multiple observables (RXJS)

Today programming exercise:

You have two buttons on website like this:
<button id="btn1">Button1</button>
<button id="btn2">Button2</button>
Subscribe to click event on those two buttons and on every click, emit text "button 1" or "button 2". Use merge method, to create one observable from two.

You can also create two intervals, that emits some value, and merge them into one observable.

Programming Exercise #4 - Observable from promise (RxJs)

Quick exercise
Goal - Create an observable from Promise. 
After two seconds from start, this should log 'hello' message. 
I suggest you to use setTimeout() method.

Programming exercise #3 - display elements from array with delay

In this exercise, I strong recommend using rxjs.

Input

Array of values (number of strings)

const arr = [1, 2, 3, 4, 5, 6];

Expected result

Display values from array with delay. For example
output 1 => one second later
output 2 => one second later
output 3 etc

Programming exercise #2 - double every property in object in array.

Hi, today exercise:

You got an array of objects, for example:

let objArr = [{id: 1, name: 'Kamil'},

{id: 2, name: 'Janusz'}, {id: 3, name: 'Mariusz'}];

Create an function, that takes this array and returns the 
same data, every id should be doubled.

You can also just display data in console.log or print fn.

let res = [{name: "Kamil", id: 2},

{name: "Janusz", id: 4},{name: "Mariusz", id: 6}]

Feel free to send your implementation in comments section!

Programming exercise #1 - find every second and add new line

Recently, I found interesting topic on SO, about parsing string in JS.
The exercise is:
Create function, that takes a string and returns string. Every second word should have added new line character "\n".
For example

let stringToParse = `How good is have account on and create new posts`
let result = "How good
is have
account on
StackOverflow and
create new
posts

Please place your answer (in any language) in comments section.