What is class library?
A class library is a pre-coded object-oriented programming (OOP) collection of templates. Both network and desktop applications use class libraries. Class libraries contain code for graphical user interface (GUI) elements such as buttons, icons, scroll bars, and windows, as well as other non-GUI components.
All OOP languages have class libraries. Languages with the .NET Framework use the Base Class Library (BCL). Java languages use the Java Class Library (JCL).
Class libraries improve code reuse by providing implementations of repetitive jobs. Writing program applications from scratch can be an extremely detailed and expensive process. Class libraries contain all essential classes in a previously written coded format, which not only simplifies programming, but also increases code quality. The customization of the class template is implemented according to the specific programming requirements.
Class libraries are continuously updated and tested for reliability to reduce programming language restrictions. This is especially true for platform-independent languages such as Java.