mkczarkowski

// Do celu =>! (if you know what I mean) 
Adder.prototype.addToArray = function (arr) {
  return arr.map(x => x + this.value);
}

mkczarkowski

const Adder = (val) => {
  this.val = val;
}

const addTwo = new Adder(2); // TypeError: Adder is not a constructor

mkczarkowski

const algoSmart = {
  likes: 52,
  getLikes: () => console.log(this.likes),
  setLikes: function(value) {
    this.likes = value;
  },
};

algoSmart.getLikes(); // undefined
algoSmart.setLikes(100000); 

mkczarkowski

<button id="example">Click me</button>

mkczarkowski

.on {
  background-color: #0288d1;
}

mkczarkowski

button = document.querySelector('#example');

button.addEventListener('click', () => {
  console.log(this); // Window!
  this.classList.toggle('on');
});

mkczarkowski

const myPreciousSecret = `I <3 AlgoSmart`;
															 
console.log(myPreciousSecret); // "I <3 AlgoSmart"
console.log(typeof myPreciousSecret); // "string"
console.log(myPreciousSecret.length); // 14

mkczarkowski

// Pre-ES6.
var myFavouriteMeal = "Pizza";

console.log('I love ' + myFavouriteMeal + '!'); // "I love Pizza!"

// ES6.
const myFavouriteMeal = "Pizza";

console.log(`I love ${myFavouriteMeal}!`); // "I love Pizza!"

mkczarkowski

console.log(`2 + 2 = ${2+2}`); // "2 + 2 = 4"
console.log(`2 + 2 = ${add(2, 2)}`); // "2 + 2 = 4"
console.log(`Is Marcin 23 years old? ${true || false}`;`) // "Is Marcin 23 years old? true"

mkczarkowski

var message = [
	  'Dużo linijek, ',
	  'dużo problemów.'
	].join('\n');

var message = 'Dużo linijek, \n' +
              'dużo problemów.';