Arrow functions

arrow.js

// Example is from = https://www.javascripttutorial.net/es6/javascript-arrow-function/

// Normal/Traditional function
function Car() {
    this.speed = 0;

    this.speedUp = function (speed) {
        this.speed = speed;
        let self = this;
      // Creates it's own scope. You have to create another variable to access the upper scope
        setTimeout(function () {
            console.log(self.speed);
        }, 1000);

    };
}

let car = new Car();
car.speedUp(50); // 50;


// Arrow function

function Car() {
    this.speed = 0;

    this.speedUp = function (speed) {
        this.speed = speed;
      // No need to create a new variable. You can directly access the variable
        setTimeout(
            () => console.log(this.speed),
            1000);

    };
}

let car = new Car();
car.speedUp(50); // 50;