Mastering ES2015 Arrow Functions: Simplify Your JavaScript Code

ES2015 has been officially released, and one of its highlights is the arrow function, which can greatly simplify the traditional function (args) { statements; } syntax.

Some basic syntax:

(param1, param2, …, paramN) => { statements }

(param1, param2, …, paramN) => expression
// equivalent to:
// (param1, param2, …, paramN) => { return expression; }

Note that an arrow function does not create its own this context; instead, it uses the this from the surrounding scope.

function Person() {
  this.age = 0;
  setInterval(() => {
    this.age++;
    // |this| properly refers to the person object
  }, 1000);
}
var p = new Person();

This eliminates the need to assign that = this as in traditional approaches, saving time and effort.