C Libraries and the Java APIs

Both C and Java have built-in libraries that you can access when writing your programs. The C libraries are somewhat limited in scope and consist mostly of functions and constants. You can import C libraries into your program using #include statements placed at the top of your program.

One of the great strengths of the Java language is the enormous collection of code libraries that you can utilize when developing your programs. The Java libraries are more commonly referred to as the Java Application Programming Interfaces (APIs). The Java APIs cover everything from I/O to GUI development to security and anything in between. The APIs consist of a collection of classes and interfaces organized in groups called packages. You can import part or all of a package into your program by placing import declarations at the top of the program. As well as providing a lot of useful methods and constants, the Java APIs include the class declarations that constitute a rich and sophisticated source of reusable code for your Java applications.