Today I Learned

hashrocket A Hashrocket project

Ruby knows itself

An identity function according to wikipedia is defined as:

> a function that always returns the same value that was used as its argument.

This morning I learned that Ruby added an identity function for objects in 2.2, #itself!

> [1, 2, 3].map(&:itself)
[1, 2, 3]

Off the top of my head I can’t think of a good example, but it does come up now and again. The identity function is definitely something to keep in mind!

Looking for help? Each developer at Hashrocket has years of experience working with Ruby applications of all types and sizes. We're an active presence at Ruby conferences, have written some of the most popular gems, and have worked on many of the web's Ruby on Rails success stories. Contact us today to talk about your Ruby project.