Welcome to the Treehouse Community

The Treehouse Community is a meeting place for developers, designers, and programmers of all backgrounds and skill levels to get support. Collaborate here on code errors or bugs that you need feedback on, or asking for an extra set of eyes on your latest project. Join thousands of Treehouse students and alumni in the community today. (Note: Only Treehouse students can comment or ask questions, but non-students are welcome to browse our conversations.)

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and a supportive community. Start your free trial today.

JavaScript

brandonlind2
brandonlind2
7,823 Points

can someone explain these []?

I'm seeing alot of square brackets within functions parentheses on mdn, but I'm not sure what they mean? for example

array.splice(start, deleteCount[, item1[, item2[, ...]]])

1 Answer

Steven Parker
Steven Parker
216,012 Points

As used in documentation, they mean "optional". So for your example:

array.splice(start, deleteCount[, item1[, item2[, ...]]])

This shows that the splice method can take as few as 2 arguments (start and deleteCount), but it can take more (items to be added), with no obvious limit.