TYPES OF DATA

TYPES OF DATA

As we know that data means collection of facts, therefore, we need symbols for their representation. These symbols may be letters, words or figures. For example 3 books, 25 students, 23rd March, 40 Watt, PIA, 140847, each item conveys different meanings. In computers data items can be classified into following three types.

1. Numeric Date
2. Alphabetic Data
3. Alphanumeric Data

NUMBER SYSTEM

Digital computers are machines which responds numbers rather than letters. All the data and instructions must, therefore, be supplied in the coded numeral format. These numerals have specific meaning for computers. Thus number systems are very important to understand because the design and organization of a computer is dependent upon the number systems. The decimal system for counting has been so widely adopted that we rarely consider the possibilities of other number system. However, the binary number system, has proved the most natural and efficient system for machine use.

THE DECIMAL NUMBER SYSTEM

The decimal number system consists of 10 digits namely 0 to 9. A number written using these digits is called a decimal number. The value of each digits in a number depends upon the following:

• The face value of the digit, i.e. the digit itself
• The base of the system.
• The position of the digit in the number

THE BINARY NUMBER SYSTEM

In representing data by ON-OFF switch position there are only two possibilities and the corresponding numbers are 1 and 0. Binary number system is a very important number system so far as the digital computers are concerned. The binary digits are abbreviated to BITS. The word BIT stand for either of the binary digits 0 or 1. Since the system has only two digits, therefore, in the binary system the base is 2. Thus all the numbers in the binary system are written with the help of the digits 0 and 1. The positional value or place value of each digit.

NUMBER CONVERSION

Human normally deals with decimal number system while binary is needed for porcessing in digital computers other number systems are used for coding and storage purposes. Thus inter-conversion of number from one number system into other number system becomes important for compulation and data processing in digital computers.

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