Download Introduction

CMSC 202 Introduction
CMSC 202
Fall 2012
Instructors & Lecture Sections
• Mr. Max Morawski
– Section 01
• Mr. John Park
– Section 06 and 11
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Course Format
2 Exams (15% each)
30%
1 Comprehensive Final Exam
20%
10 Lab Assignments (1% each)
10%
5 Projects (6, 7, 8, 9, 10%)
40%
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Project Policies
• Cheating:
– If you any of your code shows up in someone
else’s projects, the minimum penalty is a zero
for that project. You could also fail the course
or possibly get expelled.
– There is a VERY high chance of getting
caught. Last semester we caught around 20
students.
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Project Policies
• Projects must be submitted on time. Late
projects will receive a zero.
• You may submit exactly one project a
semester up to three days late with no
reduction of grade.
• If you believe your grade is incorrect, you
may contest it with your instructor within
one week of getting your grade back.
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What is CMSC 202?
• An introduction to
– Object-oriented programming (OOP) and
object-oriented design (OOD)
– Basic software engineering techniques
• Strong emphasis on proper program
design and maintainability
• Tools
• Java programming language
• Eclipse integrated development environment
(IDE)
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Course Web Site
www.cs.umbc.edu/courses/undergraduate/202/fall12
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Why Java for 202?
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•
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Popular modern OO language
Wide industry usage
Used in many types of applications
Duke, the Java Mascot
Desirable features
– Object-oriented
– Portability (cross-platform)
– Easy handling of dynamic variables
– Garbage collection
– Built-in GUI libraries
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Some Java
Background
James Gosling*
• Created by Sun Microsystems team led by James Gosling (1991)
• Originally designed for programming home appliances
– Writing a compiler (translation program) for each type of appliance
processor would have been very costly.
– Solution: use a two-step translation process
• compile, then
• interpret
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*Wikipedia, 8/12
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Interpreters, Compilers, and the
JVM
Interpreted Languages (e.g. JavaScript, Perl, Ruby)
source code translate &
execute
interpreter
Interpreter translates source into binary and
executes it
Small, easy to write
Interpreter is unique to each platform (operating
system)
Compiled Languages (e.g. C, C++)
source code
compile
binary code
compiler
execute
Compiler is platform
dependent
command
Java
source code
compile
Java compiler
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bytecode
translate &
execute
Bytecode is platform
independent
JVM is an interpreter that
Java Virtual Machine is platform dependent
(JVM)
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Sample C++ Compilation &
Linkage
Linux C++
code library
binary library
code
Linux
C++
compiler
Any
text editor
Linux C++
binary
Linux
linker
Linux C++
executable code
C++ source
code
Windows
C++
compiler
Windows C++
binary
Windows
linker
Windows C++
executable code
binary library
code
Windows C++
code library
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Sample Java Compilation,
Interpretation, & Linkage
Any text
editor
Java source
code
Any Java
compiler
(Linux,
Windows,
etc.)
Java
Runtime
Environment
(JRE)
for Linux
Java bytecode
Java
Runtime
Environment
(JRE)
for Windows
JRE contains
•The Java API binary code
•The Java Virtual Machine (JVM),
which translates and runs the Java
bytecode
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A Peek at Python vs. Java
Python
Java
public class Hello {
public static void main(String[] args) {
int quotient;
System.out.println("Hello, world");
quotient = 3 / 4;
if (quotient == 0) {
System.out.print("3/4 == 0");
System.out.println(" in Java");
} else {
System.out.println("3/4 != 0");
Some things to note regarding Java:
}
• Everything has to be in some class
}
• We need a “main()” procedure (method) }
print "Hello, world"
quotient = 3 / 4
if quotient == 0:
print "3/4 == 0",
print "in Python"
else:
print "3/4 != 0"
•
•
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Statements end with “;”
Variables must be declared
“if/else” syntax different
Statement blocks demarcated by “{...}”
Much that is similar
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A Peek at the Eclipse IDE
• Integrated Development Environment
(IDE) for writing Java programs. Contains
(minimally):
–
–
–
–
text editor
debugger
Java compiler
Java JVM
• Free download for Windows/Linux/Mac
– See course “Resources” page on the CMSC 202
web site
• Available in all OIT labs around campus
– We’ll show you more in Lab 1
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Eclipse IDE Screenshot
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