CS1150 Principles of Computer Science Introduction

Transcription

1 Principles f Cmputer Science Intrductin Yanyan Zhuang Department f Cmputer Science UC. Clrad Springs

2 Intr f Intr Yanyan Zhuang PhD in netwrk systems yzhuang@uccs.edu Office ENGR 184 Office hurs M/W: 12:05pm 12:50pm TA: Abdullah Abu Muzah aabumuz@uccs.edu Tutring: Tuesday/Thursday 5 7pm, ENGR 232 Recitatin: Wednesday, 1 2:30pm, ENGR 187 (changed this mrning, dh!) Canvas: annuncement, assignment, tests (need t pt in) UC. Clrad Springs

3 Outline What will yu learn? Lectures, Assignments, Exams Curse plicy Overview UC. Clrad Springs

4 What will yu learn? Prgramming with emphasis n cmputer science cncepts Particularly n the cncepts f abstractin in prblem slving Primitive data types Selectin statements Lps and methds Arrays, strings and text UC. Clrad Springs

5 Lectures, Assignments, Prject, Exams Lectures Mnday and Wednesday, ENGR 138 Assignments (individual) Java prgramming assignments Attendance Midterm and Final (in class, nline, pen-bk/ntes) Midterm: TBD Final: Dec 10, 10:20am 12:20pm Syllabus UC. Clrad Springs

6 Intrductin UC. Clrad Springs

7 Prgramming Cmputer prgrams, knwn as sftware, are instructins t the cmputer We (prgrammers) tell a cmputer what t d thrugh prgrams Cmputers d nt understand human languages (Siri, dh!), need t use cmputer languages t cmmunicate with them Mst prgrams are written using (high-level) prgramming languages UC. Clrad Springs

8 Prgramming Languages The high-level languages are English-like and easy t learn and prgram Fr example, the fllwing is a high-level language statement that cmputes the area f a circle with radius 5: area = 5 * 5 * ; We will learn Java in this curse What are the ther prgramming languages available? UC. Clrad Springs

9 Let s create ur first Java prgram! Please pen Eclipse: T create a prject File à New à Prject à Java prject (e.g., ) à Finish T imprt existing cde File (with src selected) à Imprt à Select General/Archive File à Brwse à Finish T create new cde File (with prject selected) à New à Other à Class à Fill in name à Finish T find the lcatin f yur cde Prject à Prperties (lk fr Lcatin) Windws: C:\Users\username\eclipse-wrkspace\prject_name Mac: /Users/username/Dcuments/eclipse-wrkspace/prject_name Cde is under prject_name\src\ (Windws) r prject_name/src/ (Mac) Eclipse vide tutrial: Skip things that yu dn t understand UC. Clrad Springs

10 Anatmy f a Java Prgram 1. Class name 2. Main methd 3. Statements 4. Statement terminatr 5. Reserved wrds 6. Cmments 7. Blcks UC. Clrad Springs

11 Class Name Every Java prgram must have at least ne class. Each class has a name (same name as.java file) By cnventin, class names start with an uppercase letter In this example, the class name is Welcme // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

12 Main Methd In rder t run a class, the class must cntain a methd named main The prgram is executed frm the main methd // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

13 Statement A statement represents an actin r a sequence f actins The statement System.ut.println("Welcme t Java!") is a statement t display the greeting "Welcme t Java! // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

14 Statement Terminatr Every statement in Java ends with a semicln (;) // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

15 Reserved wrds Reserved wrds r keywrds Wrds that have a specific meaning t Java and cannt be used fr ther purpses in the prgram Fr example, when Java sees class, it understands that the wrd after class is the name fr the class // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

16 Blcks A pair f curly braces in a prgram frms a blck that grups a cmpnent f a prgram public class Test { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); Methd blck Class blck UC. Clrad Springs

17 { Dentes a blck // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

18 ( ) Used with methds T grup tgether arguments // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

19 // Anther kind f cmments is /* */ Blck cmment // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

20 " " D nt use fr Strings // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

21 Special Symbls Character Name Descriptin { () [] // " " ; Opening and clsing braces Opening and clsing parentheses Opening and clsing brackets Duble slashes Opening and clsing qutatin marks Semicln Dentes a blck t enclse statements. Used with methds. Dentes an array. Precedes a cmment line. Enclsing a string (i.e., sequence f characters). Marks the end f a statement. UC. Clrad Springs

22 Identifiers An identifier is A name chsen by the prgrammer fr: classes, methds, variables, and cnstants // This prgram prints Welcme t Java! public class Welcme { public static vid main(string[] args) { System.ut.println("Welcme t Java!"); UC. Clrad Springs

23 Let s d mre practice! T imprt ur cde File à Imprt à Archive File à Brwse (find yur dwnladed zip file) à Open MyFirstWrds, MyFirstLines UC. Clrad Springs

24 Prgramming Style and Dcumentatin Apprpriate Cmments Naming Cnventins Prper Indentatin and Spacing Lines Write pseudcde UC. Clrad Springs

25 Apprpriate Cmments Include a summary at the beginning f the prgram t explain what the prgram des /* */ (blck cmment) Include yur name, class sectin, date, and a brief descriptin at the beginning f the prgram /* Prgrammer: Yanyan Zhuang * Class: CS 1150 * Purpse: Print a string t the cnsle * Date mdified: 6/6/2018, 6/11/2018 */ Use // abve r after a line f statement t indicate its purpse, when necessary (single-line cmment) UC. Clrad Springs

26 Naming Cnventins Chse meaningful and descriptive names Class names: Capitalize the first letter f each wrd in the name. Fr example, the class name CmputeExpressin A name cannt cntain spaces CmputeExpressin, nt Cmpute Expressin UC. Clrad Springs

27 Prper Indentatin and Spacing Indentatin Indent the same cde blcks with the same indentatin level Spacing Use blank line t separate segments f the cde (CmputeExpressin) UC. Clrad Springs

28 Write pseudcde Nt real cde Get back t this in a bit!! UC. Clrad Springs

29 Summary Java prgram Prgramming style Data types and calculatin UC. Clrad Springs