April 2018
Beginner to intermediate
426 pages
10h 19m
English
Arrow functions are a great way of simplifying the syntax of functions in ES2015. Consider the following example:
var circleAreaES5 = function circleArea(r) {
var PI = 3.14;
var area = PI * r * r;
return area;
};
console.log(circleAreaES5(2));
We can simplify the syntax of the preceding code to the following code:
const circleArea = r => { // {1}
const PI = 3.14;
const area = PI * r * r;
return area;
};
console.log(circleArea(2));
The main difference is in line {1} of the example, on which we can omit the keyword function using =>.
If the function has a single statement, we can use a simpler version, by omitting the keyword return and the curly brackets as demonstrated in the following code snippet:
const circleArea2 = r ...