Prof. Rommel Anthony Palomino Department of Computer Science and Information Technology

Introduction to Programming<Lecture 2>

Prof. Rommel Anthony PalominoDepartment of Computer Science and

Information TechnologySpring 2011

Rommel AB Palomino - UDC Spring 2011

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Number Systems and Conversions

0010 0000 0001 0010

0000

20212223

2 01 2


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Number Systems and Conversions Numbers can be represented in many ways

There exist many Numeral System or ways to represent numbers.

Their representation depends on something called BASE

BASE - 1 is the maximum number you can represent using a single digit. Base 10 Max number using single digit = 10 – 1

= 9


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Number Systems and Conversions The most well known numeral system is the

Decimal System. The one you use everyday. Base 10 It consist of 10 elements from 0-9.

Besides decimals, there exists others such as: Binary: Base 2. Uses 2 elements. 0 to 1 Octal: Base 8. Uses 8 elements. 0 to 8. Hexadecimal: ????


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Number Systems and Conversions Hexadecimal: Uses up to 16 digits. From 0 to 15 ???

Hex Dec0 01 12 23 3… …9 9A 10B 11C 12D 13E 14F 15


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Number Systems and Conversions Hexadecimal: Uses up to 16 digits. From 0 to 15 ???

Hex Dec0 01 12 23 3… …9 9A 10B 11C 12D 13E 14F 15

FF16 = 25510


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Conversion: Decimal to Binary Method:

Continuously divide the number by 2 get the remainder (which is either 0 or 1) get that number as a digit of the binary form of the

number get the quotient and divide that number again by 2 repeat the whole process until the quotient reaches 0 or

1 we then get all the remainders starting from the last

remainder, and the result is the binary form of the number

NOTE: For the last digit which is already less than the divisor (which is 2) just copy the value to the remainder portion.


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Conversion: Decimal to Binary Example

Convert 15010 to Binary

Solution: 10010110 = 150

Number Base Quotient Remainder

150 2 75 075 2 37 137 2 18 118 2 9 09 2 4 14 2 2 02 2 1 01 2 0 1


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Conversion: Binary to Decimal Method:

we multiply the binary digit to "2 raised to the position of the binary number"

We then add all the products to get the resulting decimal number.


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Conversion: Binary to Decimal Example

Convert 111001012 to Decimal0: 12: 45: 326: 647: 128

Solution: 229


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Conversion: Binary to Hexadecimal Method:

Partition the binary number into groups of 4 digits (from right to left)

pad it with zeros if the number of digits is not divisible by 4

convert each partition into its corresponding hexadecimal digit


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Conversion: Binary to Hexadecimal Example

Convert 111001012 to Hexadecimal

Solution:


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Programming Fundamentals


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Introduction to Java The original motivation for Java

The need for platform independent language that could be embedded in various consumer electronic products.


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Introduction to Java The Java technology is:

A programming language A development environment An application environment A deployment environment


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Introduction to Java As a development environment, Java

technology provides you with a large suite of tools: A compiler An interpreter A documentation generator, etc


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Java Features Some features of Java:

The Java Virtual Machine Bytecode Garbage Collection


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Java Features Java Virtual Machine (JVM)

an imaginary machine that is implemented by emulating software on a real machine

provides the hardware platform specifications to which you compile all Java technology code


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Java Features Bytecode

a special machine language that can be understood by the Java Virtual Machine (JVM)

independent of any particular computer hardware, so any computer with a Java interpreter can execute the compiled Java program, no matter what type of computer the program was compiled on


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Java Features Garbage collection thread

responsible for freeing any memory that can be freed. This happens automatically during the lifetime of the Java program.

programmer is freed from the burden of having to deallocate that memory themselves


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How a Java Program works?


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Exercise Write a flowchart for

How to answer and end a phone call in your Cellphone


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Questions?


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For Next Class We will do our first Java Program and will learn

how to use our Programming Environment

Documents

Prof. Rommel Anthony Palomino Department of Computer Science and Information Technology