https://itnext.io/upgrading-bash-on-macos-7138bd1066ba

One thing that many macOS users don’t know is that they are using a completely outdated version of the Bash shell. However, it is highly recommended to use a newer version of Bash on macOS, because it enables you to use useful new features. This article explains how to do this.

To see how outdated the Bash version included in macOS is, execute the following command: