Page 56 - CA_Blue( J )_Class9
P. 56
• Digits: All digits of Decimal Number System (0 to 9) can be used in Java Programming.
Note: Combination of Alphabets and Digits together are known as Alphanumeric. For example, area1,
student1, kol700111, del110002, etc. are alphanumeric strings.
• Operators: A symbol or sign used to specify a function. There are three categories of operators used in Java:
1. Arithmetical Operator: The operators in this category are: +, -, /, %, *
2. Logical Operator: The operators in this category are: &&, ||, !
3. Relational Operator: The operators in this category are: ==, !=, <, <=, >, >=
• Delimiters: Special characters that separate tokens. For example, braces or separators: (,), {,}, [,], etc. and
punctuators: comma (,), semicolon (;) etc.
Note: Operators and Delimiters are also called Special Characters.
4.2 HOW CHARACTERS ARE STORED IN MEMORY?
A computer is a man-made machine that does not capable of recognising anything from the ‘human world’. To
store character values, each character is converted into a corresponding numeric code in binary form, which is
then stored in the computer’s memory. This process is known as character encoding. There are two types of
encoding procedures: ASCII code and Unicode.
4.2.1 ASCII Code
ASCII stands for “American Standard Code for Information Interchange”. It is a character encoding standard for
text files in computers, communications equipment, and other devices. It is made up of 128 symbols (i.e.,7 bits)
consisting of letters (both uppercase and lowercase), numbers, punctuation marks, special symbols and control
symbols. Numeric range of ASCII code is from 0-127. It was mainly designed to represent only basic English
characters. Extended ASCII supports 256 characters (character range 0-255).
Following table shows the ASCII value for characters with binary value and description:
54 Touchpad Computer Applications-IX

