ES6

// let & const
console.log('LET & CONST');
let variable = 'Test';
console.log(variable);
variable = 'Another value';
console.log(variable);

const maxLevels = 100;
console.log(maxLevels);
// maxLevels = 99; // Won't work

// Block scope
function reset() {
  // console.log(variable);
  let variable = null;
  console.log(variable);
}
reset();
console.log(variable);

// Arrow Functions
console.log('ARROW FUNCTIONS');
const addNumbers = function(number1: number, number2: number): number {
  return number1 + number2;
};
console.log(addNumbers(10, 3));

const multiplyNumbers = (number1: number, number2: number) => number1 * number2;
console.log(multiplyNumbers(10, 3));

const greet = () => {
  console.log('Hello!');
};
greet();

const greetFriend = friend => console.log(friend);
greetFriend('Manu');

// Default Parameters
console.log('DEFAULT PARAMETERS');
const countdown = (start: number = 10): void => {
  console.log(start);
  while (start > 0) {
    start--;
  }
  console.log('Done!', start);
};
countdown();

// Rest & Spread
console.log('REST & SPREAD');
const numbers = [1, 10, 99, -5];
console.log(Math.max(33, 99, 10, -3));
console.log(Math.max(...numbers));

function makeArray(name: string, ...args: number[]) {
  return args;
}
console.log(makeArray('Max', 1, 2, 6));

// Destructuring
console.log('DESTRUCTURING');
const myHobbies = ['Cooking', 'Sports'];
const [hobby1, hobby2] = myHobbies;
console.log(hobby1, hobby2);

const userData = { userName: 'Max', age: 27 };
const { userName: myName, age: myAge } = userData;
console.log(myName, myAge);

// Template Literals
const userName = 'Max';
const greeting = `This is a heading!
I'm ${userName}.
This is cool!`;
console.log(greeting);