Introduction to Programming Prof. Rommel Anthony Palomino Department of Computer Science and Information Technology Spring 2011

Number Systems and Conversions Rommel AB Palomino - UDC Spring 

Number Systems and Conversions Rommel AB Palomino - UDC Spring  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

Number Systems and Conversions Rommel AB Palomino - UDC Spring  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: ????

Number Systems and Conversions Rommel AB Palomino - UDC Spring  Hexadecimal: Uses up to 16 digits.  From 0 to 15 ??? HexDec …… 99 A10 B11 C12 D13 E14 F15

Number Systems and Conversions Rommel AB Palomino - UDC Spring  Hexadecimal: Uses up to 16 digits.  From 0 to 15 ??? HexDec …… 99 A10 B11 C12 D13 E14 F15 FF 16 =

Conversion: Decimal to Binary Rommel AB Palomino - UDC Spring  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.

Conversion: Decimal to Binary Rommel AB Palomino - UDC Spring  Example  Convert to Binary  Solution: = 150 NumberBaseQuotientRemainder

Conversion: Binary to Decimal Rommel AB Palomino - UDC Spring  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.

Conversion: Binary to Decimal Rommel AB Palomino - UDC Spring  Example  Convert to Decimal 0: 1 2: 4 5: 32 6: 64 7: 128  Solution: 229

Conversion: Binary to Hexadecimal Rommel AB Palomino - UDC Spring  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

Conversion: Binary to Hexadecimal Rommel AB Palomino - UDC Spring  Example  Convert to Hexadecimal  Solution:

Programming Fundamentals Rommel AB Palomino - UDC Spring

Introduction to Java Rommel AB Palomino - UDC Spring  The original motivation for Java  The need for platform independent language that could be embedded in various consumer electronic products.

Introduction to Java Rommel AB Palomino - UDC Spring  The Java technology is:  A programming language  A development environment  An application environment  A deployment environment

Introduction to Java Rommel AB Palomino - UDC Spring  As a development environment, Java technology provides you with a large suite of tools:  A compiler  An interpreter  A documentation generator, etc

Java Features Rommel AB Palomino - UDC Spring  Some features of Java:  The Java Virtual Machine  Bytecode  Garbage Collection

Java Features Rommel AB Palomino - UDC Spring  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

Java Features Rommel AB Palomino - UDC Spring  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

Java Features Rommel AB Palomino - UDC Spring  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

How a Java Program works? Rommel AB Palomino - UDC Spring

Exercise  Write a flowchart for  How to answer and end a phone call in your Cellphone 22Rommel AB Palomino - UDC Spring 2011

Questions? 23Rommel AB Palomino - UDC Spring 2011

For Next Class Rommel AB Palomino - UDC Spring  We will do our first Java Program and will learn how to use our Programming Environment