Search⌘ K
AI Features
Home
Courses
JavaScript In Practice: ES6 And Beyond

The ES6 way

Explore how ES6 introduces default arguments to manage optional function parameters effectively. Understand the syntax and rules for setting default values, how they differ from previous JavaScript versions, and best practices for optional parameters in ES6 functions.

We'll cover the following...

ES6 supports default values. Whenever an argument is not given, the default value is substituted. The syntax is quite compact:

Node.js
function addCalendarEntry( 
    event, 
    date = new Date().getTime(), 
    len = 60, 
    timeout = 1000 ) {
    return len;
}
var add=addCalendarEntry( 'meeting' );
console.log(add); //outputs the default value set earlier

Suppose function f is given with two arguments, a and b. ...