Java™ How to Program, Seventh Edition

Summary

Section 14.1 Introduction

• Data stored in variables and arrays is temporary—the data is lost when a local variable goes out of scope or when the program terminates. Computers use files for long-term retention of large amounts of data, even after the programs that created the data terminate.

• Persistent data maintained in files exists beyond the duration of program execution.

• Computers store files on secondary storage devices such as hard disks.

Section 14.2 Data Hierarchy

• The smallest data item in a computer can assume the value 0 or the value 1 and is called a bit. Ultimately, a computer processes all data items as combinations of zeros and ones.

• The computer’s character set is the set of all characters used to write programs and represent ...