encapsulation : Java Glossary

• If you need to change the code, you need to change it in only once place.
• If you need to change the code, you can change it in one place without having to make adjustments to all the code that uses it.
• You only have to debug it once. Debugging well-encapsulated code is much easier since you can test each piece independently, and you can easily localise where the problem must be.
• Since you are writing encapsulated code once and for all, you can spend more time getting it just right.
• Encapsulation makes it much easier to understand your code.
• Your encapsulated code becomes well-trusted reusable tools you can use to consruct new programs. They become units of thought in constructing new programs. You don’t have to start from the basics every time. Think of them as like modular units in construction rather than always starting from raw lumber and pipe.
• Encapsulation marks you as a professional. The hallmark of a rank amateur is a complete lack of encapsulation.

You can write encapsulated code in almost any language, even assembler. Some languages, though, like Java make it much easier.