Welcome to the Treehouse Community

Want to collaborate on code errors? Have bugs you need feedback on? Looking for an extra set of eyes on your latest project? Get support with fellow developers, designers, and programmers of all backgrounds and skill levels here with the Treehouse Community! While you're at it, check out some resources Treehouse students have shared here.

Looking to learn something new?

Treehouse offers a seven day free trial for new students. Get access to thousands of hours of content and join thousands of Treehouse students and alumni in the community today.

Start your free trial

Ruby Ruby Foundations Arrays Sorting and Comparison

Posted by chenfei
chenfei
2,707 Points

Query on ! method

When I use 

array.sort.uniq!

The array didn't actually change to unique and sorted. WHY?

1 Answer

Bob Hensley
Bob Hensley
26,781 Points

The sort method will not invoke any side effects. You need to use sort! instead.

array.sort!.uniq!

Or, alternatively:

array = array.sort.uniq
chenfei
chenfei
2,707 Points

Thanks, it works