Cracking the Java Coding Interview pdfdrive com

So that program compiled from that compiler can run on any hardware. This need led to the creation of Java.
Java Class Libraries
Java programs consist of pieces called classes. Classes consist of pieces called methods that perform tasks and return information when they complete their tasks. You can program each piece
you may need to form a Java program. However, most Java programmers take advantage of rich collections of existing classes in Java class libraries. The class libraries are also known as the
Java APIs (Application Programming Interfaces). Thus, there are really two pieces to learning the Java “world.” The first is learning the Java language itself so that you can program your
own classes; the second is learning how to use the classes in the extensive Java class libraries. Throughout the book, we discuss many library classes. Class libraries are provided primarily by
compiler vendors, but many class libraries are supplied by independent software vendors (ISVs). Also, many class libraries are available from the Internet and World Wide Web as freeware
or shareware. You can download free ware products and use them for free—subject to any restrictions specified by the copyright owner. You also can download shareware products for free,
so you can try the software. Shareware products often are free of charge for personal use. However, for shareware products that you use regularly or use for commercial purposes, you are
expected to pay a fee designated by the copyright owner. Many freeware and shareware products are also open source. The source code for open-source products is freely available on the
Internet, which enables you to learn from the source code, validate that the code serves its stated purpose and even modify the code. Often, open-source products require that you publish any
enhancements you make so the open-source community can continue to evolve those products. One example of a popular open-source product is the Linux operating system.