The Java alphabet
We can think of the Java alphabet as consisting of all the characters one could type on a standard English keyboard, for example, the digits, uppercase and lowercase letters, and special characters such as +, =, <, >, & and %.
More formally, Java uses the ASCII (American Standard Code for Information Interchange, pronounced ass-key) character set . This is a character standard which includes the letters, digits and special characters found on a standard keyboard. It also includes control characters such as backspace, tab, line feed, form feed and carriage return. Each character is assigned a numeric code. The ASCII codes run from 0 to 127
The programs in this series will be written using the ASCII character set which, can be viewed here.
Technical note: In reality, Java uses the Unicode character set. For starters, it includes the ASCII character set. But Unicode also includes all characters in most written languages in the world. In order to represent so many characters Unicode uses two bytes (16 bits) for storing each character. With 16 bits, one can store 2^16 = 65,536 different codes. Unicode is especially useful if one is writing a program for use by people speaking different languages. In this series, we use only the English alphabet.
In the next article, we will take a look at Java tokens.