Install and use libraries

- [Instructor] Computer languages…such as Java, C++, and Python,…all have ecosystems.…The ecosystems contain Libraries that provide…functionality that is not included…within the core language.…Java has a particularly rich ecosytem.…Part of gaining proficiency with a language…is learning how to use its ecosystem.…In Java, most Libraries are distributed…as Java archive files, known by their extension…J-A-R.…

Jar files may or may not contain source code.…There are distinct differences between…using Libraries at compile time…and using Libraries at run time.…It is relatively easy to use Libraries at compile time,…and IDE's, such as IntelliJ,…provide assistance for using Libraries.…It is more difficult to use Libraries at run time,…particularly when your code will be installed…into a server,…or a UI such as an Ant or a device,…or a cloud-based application.…

Some of the difficulties include…ensuring that Libraries are installed…in correct locations, ensuring that your code…can access Libraries, and resolving conflicts…between different versions of Libraries…