CSC116: Introduction to Computing - Java

Intro to CSC116

Course Information

• Introductions

• Website

• Syllabus

Computers

First Java Program

• Text Editor

• Helpful Commands

• Java Download

Instructors• Course Instructor:

– Mrs. Michelle Glatz, mlglatz@ncsu.edu

• Office: Daniels 223

• Office Hours:

– OnLine: Sundays 9-10pm

– On-Campus: Tuesdays 5-6 pm in Daniels 200

– By appointment – set up via email

• Support email: group-csc116-glatz+601@ncsu.edu

• TA:

– Rui Shu, rshu@ncsu.edu

•Online Office Hours: Fridays 7-9 pm

Office Hours• On-Line Office Hours: Dedicated time to

answering questions via Piazza, email, or Google Hangout

• CSC116 On-campus Office Hours:

– http://go.ncsu.edu/csc116teachingstaffofficehours

– We use My Digital Hand during on-campus office hours to manage questions:

• http://mydigitalhand.org

Textbook• Building Java Programs

A Back to Basics Approach4th EditionReges and Stepp

• NCSU CSC Department, Style Guidelines

Course WebsiteEngineering Online course homepage:

Links to:

– Syllabus

– Video Lectures

– Moodle page

Moodle login page:

• http://wolfware.ncsu.edu

• Moodle Course Page (direct link)

– course materials– submit coursework– feedback returned– grade book

Moodle • Syllabus Link

– Syllabus

• Schedule Link

– Schedule

– All Lab-Exercises are due on Sunday night

Including those designated as in-class exercises.

•Assignments due at 11:45 pm

Course Structure

• The course structure is a mixture of lecturing and practicing as we go through material.

• The idea is to reinforce the learning of new material with hands on experience using it right away.

Exercises• In-class: Meant to be completed while watching

the lecture. Due Weekly.

• Lab: Apply new concepts. Due Weekly.

• Practice-It! Exercises: Every 2 chapters turn in list of problems solved as Homework (screenshot pdf: cntrl-P, capture your userid)– https://practiceit.cs.washington.edu/

– create an account

– choose a problem from list

– Type a solution and submit it.

– The system will test it and tell you whether your solution is correct.

Programming Assignments

• There will be 6 programming projects in addition to the Lecture Exercises.

• MUST BE DONE INDIVIDUALLY!!

Academic Integrity

• Do your own work (projects)

– Don’t copy from outside resources (don’t google it!)

– Don’t look at other student’s code

– Don’t show your code to another student

• See syllabus for violation penalties

Exams

• Two midterm exams

• One final exam

• Check the course schedule on our website for dates. You will have a 2-day exam window.– Schedule a time with your proctor at any time during

this window.

• Paper exams, closed book, closed notes, closed computer.

Message Board• The course message board (Piazza) is a

great place to ask questions and discuss topics with the Instructor, TAs, and all the other students in class– piazza link

• The only rule is that you may not publicly post any code that directly comes from an assignment, but example code is permitted

• Make the question private if need to post your code.

• Post to Group 601 if specific to our section

Grading• Minimum Grade Requirement

➢ Need a 73 to advance to CSC216➢To earn a C- or higher you must:

•have an exam average of at least 60AND

•have a project average of at least 60Activity Weight

Exercises:(.2 * In-class avg + .6 * Weekly Exercise avg + .2 * Practice-it! avg)

14

Projects 30

Comprehensive Exercise 2

Exam 1 17

Exam 2 17

Final Exam 20

Regrade Requests

• The TA’s will send out an email to inform you when they have completed grading of each assignment.

• To request a regrade (within one week):➢ Send an email to the Teaching Staff support email

with Regrade Request as the subject line.

➢ group-csc116-glatz+601@ncsu.edu

➢ Include the name of the assignment and why you think it should be regraded.

What you will learn in CSC116…

• Problem solving – the purpose of writing a program is to solve a problem

• Java programming language

• Concepts of Object-Oriented Programming (OOP) – encapsulated collection of data variables and methods

• Documentation techniques

• Testing methods

Hardware

• The physical components that make up a computer:

– CPU (Central Processing Unit)

•Executes program instructions (brains)

– Memory (RAM)

•Used to store current program and data

– Hard Disk

• Permanent data storage

Software

• Computer programs

• Operating System

• Bridge between hardware, programs, user

• Allocates memory and send instructions to CPU

• Applications

• Programs run within the operating system

Binary and Decimal

• Typically, we (humans) use the base-10 (decimal) notation.

– Uses the digits 0 through 9

• All information is stored on a computer as binary numbers– 1’s and 0’s (base 2)

– 10 (1 * 21 + 0 * 20) = 2 base-10

– 11 (1 * 21 + 1 * 20) = 3 base-10

– 100 (1 * 22 + 0 * 21 + 0 * 20) = 4 base-10

Binary and Decimal

• Binary (Base-2)

• Decimal (Base-10)

24 23 22 21 20

16 8 4 2 1

104 103 102 101 100

10,000 1,000 100 10 1

Convert between Decimal and Binary

• 20 Decimal to Binary (20 – 16 = 4, 4 – 4 = 0)

• 1 1 1 0 0 Binary to Decimal

16 + 8 + 4 + 0 + 0 = 28

24 23 22 21 20

1 1 1 0 0

16 8 4 0 0

Bits and Bytes

• Bit – Binary Digit

• Byte – 8 Bits

• Kilobyte (KB) 210 – 1024 bytes

• Megabyte (MB) 220 – 1,048,576 bytes

• Gigabyte (GB) 230 – 1,073,741,824 bytes

Programming Languages• We can write a program using only 0s and 1s, but that

has many disadvantages

– Hard to look at and understand

– Very tedious!

• We use a programming language instead - we write code in English instead of 0s and 1s, which is much easier to read and understand

• The code we write is interpreted by a program called a compiler, which translates our English into 0s and 1s for the processor to understand

• Java is the programming language we will use in this course

Computer Programming

• Algorithm - A step‐by-step description of how to accomplish a task.

• Program – A list of instructions to be carried out by a computer.

• Computer Programming – the art of designing and writing a group of instructions that the computer’s processor executes.

Software• You may download the Java 2 Standard Edition (J2SE) Software

Development Kit (JDK) from http://www.oracle.com/technetwork/java/javase/downloads/index.html

– Download JDK version 8u191, DO NOT download version 11.

• Text Editor• Mac

• TextWrangler, Aquamacs

• Windows• Notepad++

• Configure to convert tabs to 4 spaces :– Notepad++ : Settings->Preference->Language

Set Tab size to 4 Check Replace by space box

- TextWrangler : Preferences->Editor Defaults->Auto-expand tabsSet tabs to 4 spacesrestart TextWrangler for

changes to take place

Java Download for Laptop

• The next set of slides show the java download and set up process.

• The current version on the download site is Version 11.– We will be using version 8

• The java version used for demonstration is version 8 update 152 (current version is 191)

• http://www.oracle.com/technetwork/java/javase/downloads/index.html

Download JavaCurrent Download is Version 11, don’t download this one.

Download JavaPage down to the following Version 8 downloads. Click

on the JDK download

Accept Agreement

Installation• Save the file to the desktop and run it• Install to default location

The installation screen should read (don't change it):

Install to:C:\Program Files\Java\jdk1.8.0_152\

Installation

Install Directory

Setting the Path – Windows• Once the installer is finished, you must set your computer's path

before Java will work correctly – FOR WINDOWS ONLY

➢Go to the Control Panel and double-click System

➢ Select the Advanced tab

➢Click on the Environment Variables button

➢ Look under System Variables for "Path"Click on "Path" and then click edit

➢Add the following to the end of the Path:

;C:\Program Files\Java\jdk1.8.0_152\bin

• Click OK.

Setting CLASSPATH - Windows

• Look to see if there is a variable named CLASSPATH

• If there is not, then Click the "New" button.

➢ For the variable name, type:

CLASSPATH

➢ For the value, type: .; (that period semicolon)

➢Click OK. Exit out of all the open windows

Installed Correctly?• Open up a command prompt.

– On Windows:

➢ Open Command Prompt

- On MAC OSX:

➢ Open the Applications folder,

open the Utilities folder, then open the Terminal application.

• Type java and hit enter

➢ "command not found“ means java is not installed correctly

➢ list of options for running java means installed ok

• Type java -version and hit enter

➢ It should list version you installed (e.g. 1.8.0_152)

Write Compile Execute • A human writes Java code, known as source code (.java file)

– Type a HelloWorld program in your editor and save as HelloWorld.java

• The Java compiler converts the source code into machine code or byte code (.class file)

– javac HelloWorld.java

• The computer has a Java Virtual Machine (JVM), which translates the byte code into instructions that the specific computer’s processor can understand.

– java HelloWorld

• A .class file can be used on any computer that has a Virtual Machine, no matter what platform the class file was created on (platform independence)

• Output – messages printed to the screen

Function Unix MS-DOSChange directory cd cd

Directory list ls dir

Copy files cp copy

Move files mv move

Delete files rm del

Make directory mkdir mkdir

Delete directory rmdir rmdir

Handy Commands used on the command line

UNIX Command Help

• See the E115 Textbook

(http://ncsu.orgsync.com/org/e115/)

Traverse Directory Tree

• cd (change directory)

• cd .. (move up to next higher directory)

• cd ../../.. (move up multiple directories)

• cd ~ (move to home dir, unix only)

• cd / (move to root directory)

What’s in a directory?

• ls list contents of directory (unix)

• ls -l list the contents in long format (all information, size, date, owner, etc.) (unix)

• dir list contents of directory (ms-dos)

• ls -a list ALL files, even "." (dot) files and hidden files (unix)

• ls -la lists ALL files in long format (unix)

• dir /a lists ALL files in long format (ms-dos)

Organize your CSC116 Files

• mkdir – make directory

• Try it (start in home directory):– mkdir csc116

– cd csc116

– mkdir exercises

– mkdir projects

– cd exercises

– mkdir Lab1

– cd Lab1

Helpful Tricks/Shortcuts

• Up/Down arrows – Recall previous commands

• Tab completion – Completes commands/file names

• Ctrl + C – to regain command prompt if system is “hung up”

Classic First Program• Write a program that prints the text “Hello, World!” to the

screen

public class HelloWorld {

public static void main(String[ ] args) {

System.out.println(“Hello, World!”);

}

}

RULE:

The name you give your class MUST be the same name you give your file. Thus, the above program must be saved in a file called HelloWorld.java

During Lecture Assignment• Go to our Moodle page and work on the

HelloWorld.java assignment:/**

* This is an example class that illustrates printing a message to the screen

*

* @author YOUR NAME

*/

public class HelloWorld {

public static void main(String[] args) {

System.out.println("Hello World! My name is [put your name here].");

System.out.println("I [am new to programming, have done some Java/C/etc. programming].");

System.out.println("I live in [city, state (country if not usa)]."); System.out.println("I [work as a Y at company X, am a full-time student, etc.]"); System.out.println("I use a [pc, mac, etc] with the [Windows 7/8/10, OSX, Linux, etc]

operating system.");

}

}