CS201 RECITATION 1. Introduction to C++

Transcription

1 CS201 RECITATION 1 Introduction to C++

2 Outline Part 1 : Writing and debugging code with CodeBlocks Part 2 : Porting, compiling and testing in Dijkstra Part 3 : Using and understanding header files

3 Part 1: Writing and debugging code with CodeBlocks Consider the following class:

4 Let s modify the GradeBook class such that it keeps the midterm, final, homework, and quiz grades of a particular student as its data members it calculates a letter grade of the student using the computefinalgrade member function that takes four input grades from the user computes the average grade acc. to the following weights midterm (30%), final (35%), homework (15%), quiz (20%) assigns a letter grade according to the table 90 Grade A 80 Grade 89 B 70 Grade 79 C 60 Grade 69 D Grade < 60 Otherwise F U (unkown)

5 Let s do it using CodeBlocks CodeBlocks is an integrated development environment. Make sure you download the IDE with its MinGW compiler.

6 New C++ Project

7 New C++ Project

8 New C++ Project

9 New C++ Project

10 New C++ Project

11 New C++ Project

12 New C++ Project

13 New Source File

14 New Source File

15 New Source File

16 New Source File

17 New Source File

18 GradeBook.cpp

19 GradeBook.cpp

20 GradeBook.cpp

21 GradeBook.cpp Build & Run

22 GradeBook.cpp

23 GradeBook.cpp

24 GradeBook.cpp

25 GradeBook.cpp

26 GradeBook.cpp

27 GradeBook.cpp

28 GradeBook.cpp Alternative: Successfully Compiled!

29 GradeBook.cpp

30 GradeBook.cpp

31 GradeBook.cpp

32 GradeBook.cpp

33 GradeBook.cpp

34 GradeBook.cpp

35 GradeBook.cpp (Debugging) Breakpoint

36 GradeBook.cpp (Debugging)

37 GradeBook.cpp (Debugging) Step into

38 GradeBook.cpp (Debugging)

39 GradeBook.cpp (Debugging)

40 GradeBook.cpp (Debugging) Next line

41 GradeBook.cpp (Debugging)

42 GradeBook.cpp (Debugging) Step out

43 GradeBook.cpp (Debugging)

44 GradeBook.cpp (Debugging) Debug/Continue

45 GradeBook.cpp (Debugging) Step Into : Runs the program until the next instruction is reached. Next Line : Runs the program until the next line of code is reached. Step Out : Runs the program until the current procedure is completed. Step Out Next Line Step Into

46 At Break Point Step Into Next Line Step Out

47 Part 2: Porting, compiling and testing in Dijkstra FileZilla (FTP client) + PuTTY (SSH Client) FileZilla PuTTY SSH Secure Shell

48 Part 2: FileZilla dijkstra.ug.bcc.bilkent.edu.tr

49 Part 2: FileZilla

50 Part 2: FileZilla

51 Part 2: PuTTY

52 Part 2: PuTTY

53 Part 2: PuTTY

54 Part 2: PuTTY

55 Part 2: PuTTY

56 Part 2: PuTTY

57 Part 2: PuTTY The base command for the Gnu C++ compiler is g++ Single File Programs The easiest compilation uses the command format: g++ -o <outputname> <cppfile> Example: g++ -o myexe prog1.cpp Multiple File Programs g++ -o <outputname> <cppfile1> <cppfile2>... Example: g++ -o myprogram thing.cpp main.cpp This command compiles and links the code files "thing.cpp" and "main.cpp" together into the executable program called "myprogram. g++ -o myprogram *.cpp This command compiles and links all the code files with ".cpp" extension.

58 Part 2: SSH Secure Shell

59 Part 2: SSH Secure Shell dijkstra.ug.bcc.bilkent.edu.tr

60 Part 2: SSH Secure Shell

61 Part 2: SSH Secure Shell New File Transfer Window

62 Part 2: SSH Secure Shell

63 Part 2: SSH Secure Shell

64 Part 2: Types of error Compile Time errors Syntax errors Undeclared variables and functions, improper function calls etc. e.g. Forgetting to put semicolon(;) at the end of an instruction. Result : Linker errors Undefined functions or multiply defined functions or symbols e.g. Not including correct header files Not using the correct namespace Result :

65 Run-time errors Fatal Errors Typically cause the program to crash during execution e.g. Trying to access a non-existent memory location. Result : Non-Fatal(Logical) Errors Does not crash the program but produce erroneous results Typically hardest to detect Result : Incorrect program behaviour

66 Part 3: Using header files Why do we need header files? 1. Speeds up compilation time Upon the change of a single line of code; Without headers : All of the code needs to be recompiled With headers : Only changing parts need to be recompiled 2. Keeps the code organized Necessary for big projects Allows multiple people to work on the same project For more info : Headers and Includes: Why and How

67 Part 3: Using header files Back to GradeBook.cpp Let s try and separate this file into multiple files separating the interface of the class from its implementation as well as separating the user program that uses this code.

68 Part 3: Using header files

69 Part 3: Using header files

70 Part 3: Using header files Interface (Header,.h) File

71 Part 3: Using header files Implementation (.cpp) File

72 Part 3: Using header files Main (.cpp) File

73 Part 3: Using header files

74 Part 3: Using header files