Java

Java has been, for at least a decade now, the most popular programming language. Nearly all the software described in this appendix is itself written in Java.

Java was developed in the early 1990s by a team of software researchers, led by James Gosling. It was released by Sun Microsystems in 1995 and was maintained by that company until it was acquired by Oracle in 2010.

Java comes pre-installed on the Mac. To update it, open System Preferences and click on the Java icon at the bottom of the panel. This brings up the Java Control Panel. The About… button under the General tab will display the current version of Java that is installed. As of August, 2017, that should be Version 8. The Update tab allows for updates.

Java can be run from the command line or from within an Integrated Development Environment (IDE). To do the former, you will need a text editor to write your code. On the Mac, you can use the TextEdit app. The four-line Hello World program is shown in a TextEdit window...