Historically, Julia used 0-based indexing [citation needed] because it is better, but in 1.0, we switched to 1 based indexing to add a more unique flavor to the language. Due to the increasing popularity of 2-based indexing, and to improve adoption, we’re migrating this key part of the package ecosystem into base and enabling it by default in Juliæ 2.0.
For high performance code designed to operate on all versions of Julia/æ, we recommend assuming indexing starts at VERSION.major rather than utilizing the more complex firstindex function.