# Principles Of Software Development

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## (a) Different types of number system:-

1 binary – The binary number system can be represented by 2 digits (0 and 1) . all the data of our computer is in the form of binary numbers. Binary number is mostly used inÂ electronic circuit to check there voltages (i.e., on/off switch)Â where 0 consider when switch is off and 1 when switch is on. Moreover the base of binary number is 2 because it hasÂ only 2 digits and each binary digit is known as bit.

Examples-a (010101)2

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â B (1010.101)2

**Decimal**:- decimal number system can be represented by 10 types of digits from 0 to 9, so the base of decimal number system is 10. This is one of the most simple and familiar with everyone.

Examples-A (456374)10

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â B (143.345)10

**Octal**:-Â it can be represented by 8 different types from 0 to 7, so the base of octal is 8. The group of 3 binary digit is equal to 1 octal number. For example- 000 binary number is equal to 0, 001 binary number is equal to 1 and so on. Moreover in this octal number system any digit is always less than 8 because 8 has not a valid digit. For example-a (6342)8

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â B (2473.564)8

**Hexadecimal**:-Â hexadecimal can be represented by 16 digits from 0 to 15 but 0 to 9 can be in digits but 10 to 15 in alphabets like 10 =A, 11=B, 12=C, 13=D, 14=E, 15=F. Only complex or wide numbers are used in this system.

For example-A (CD45)16

Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â B (D77.4A6)16. (codesand tutorials)

## (b) convert 103_{10 }to binary

** Answer =** binary 1100111

Hexadecimal is 67

Octal is 147

## Â (c) Convert (1011010)_{2 }to decimal and hexadecimal.

**Answer =**

**Decimal**

**(**1011010)_{2}

(1011010)_{2} =

1×2^{6} + 0x2^{5} + 1×2^{4} + 1×2^{3} + 0x2^{2} + 1×2^{1} + 0x2^{} =

1×64 + 0x32 + 1×16 + 1×8 + 0x4 + 1×2 + 0x1 =

64 + 0 + 16 + 8 + 0 + 2 + 0 = **(90)**_{10}

**Hexadecimal is 5A.**

Â **Integer** – it consist whole number that can be positive or negative like 12, 0, -12 or 1344. But integers can’t be in decimals. It is used to search the items in the computer with the help of array. It occupy 2 and 4 bytes. And the range for signed integers is -32,468 to 32767 or -2,147,483,648 to 2,147,483,647. For unsigned the range value is 0 to 65,535 or 0 to 4,294,967,295.

Example:-Â Â Â Â Â Int id; (Techterm)

**Character** – a character may be any letter, number or symbol than can be typed on computer. There are two types of the character data types. Signed and unsigned. Each characterÂ occupy 1 byte of storage. Range of signed char is -128 to 127 and for unsignedis 0 to 255.

Example:- Char name; (techterm)

**Float** – when we want to store a decimal values in the variable than we can say this is float. It is also known as real number data type and the storage size of float is 4 bytes. The range is 1.2E-38 to 3.4E+38.

Float avg;

**Double**– when we have to use data type on big eateries that type of data is double data type. Moreover storage size of double data type is 8 bytes.

**Boolean-**when we have only two option like yes/no or true/false then we can say this type of data is known as Boolean data.

Different types of coding system

1. BCD Code

The full form of BCD is binary coded system. It has represented by 4 binary digits because it has 4 bit code. This code is mostly used in the past.

2. EBCDIC Code

EBCDIC means extended binary coded decimal interchange code which can be represented by 256 characters and it has 8 bit code.

3. ASCII

ASCII stands for American standard code for information interchange. The founder of this is ANSI (American National Standard Institute) in 1968 and mostly prefers to use on personal computer. It has 7 bit code which can be represented by 128 characters. This code is not enough to represent the graphics character on computer screen. As 8 bit character represent 256 character and the extended 128Â character has unique code represent graphic symbols.

4. Unicode

Unicode has a 16 bit code and it can be representing by 65536 characters. The main purpose of this is to replace ASCII code because it can represent all the characters of all languages in the world. (Ameen, 2011)

5 Barcode

A barcode is just like a image of small lines which shows the retails and identify the particular items. The code of the product is entered in the computer before to put on the shells. Moreover it has five main parts : a quiet zone, a start character, data character, a stop character, and another quiet zone. (manufacturingERP)