GVSU CIS 263

Week 1 / Day 1

Administrative Stuff

• Course web page: https://cis.gvsu.edu/~kurmasz/Teaching/Courses/F19/CIS263/syllabus.html
• Read the syllabus.
• Office Hours:
  • Official office hours are given on my web page. This is when I make a point of being in my office.
  • However, I tend to be on campus from 9 to 4 Monday, Wednesday, and Friday.
  • Anytime the door is open, it’s office hours. The wider the door is open, the more interruptible I am.
  • If it’s all the way open, feel free to come in just to chat.
• I like mouthy students. (More specifically, I like to know what you do and don’t like about the way the course is being run. We may not agree; but, that’s OK.)
• The primary text will be the “Data Structures Essentials” online book from zyBooks https://www.zybooks.com/catalog/data-structures-essentials/
• A Tour of C++ by Bjarne Stroustrup is a good C++ reference book that is free to GVSU students: https://learning.oreilly.com/library/view/a-tour-of/9780134998053/
• I will draw some lecture material out of the Weiss text. It’s expensive, so I’m not suggesting you run out and buy it.
• All submitted code must come with tests.
• You are generally expected to fix and re-submit buggy code. Your grade will be based primarily on timliness (which a penalty for each buggy submission).

Getting started with C++

• Why C++?
  • Closer to the hardware
  • Languages like Java abstract away a lot of implementation details.
    • This is good when doing “ordinary” application development; but,
    • it is important for Computer Science majors to know what’s going on “under the hood”.
    • You won’t need to look “under the hood” often; but, if you don’t learn it in college, you won’t have the skill when you need it.
  • Also an opportunity to get experience with more languages.
  • To be marketable after graduation, you need to be able to learn new languages / platforms quickly.
• Skill Level
  • You need only learn C++ well enough to complete the assignments. (This isn’t a C++ class, after all.)
  • However, the Weiss text goes into a level of detail that will be useful if you anticipate doing some “serious” C++ development after graduation.
    • https://www.pearson.com/us/higher-education/program/Weiss-Data-Structures-and-Algorithm-Analysis-in-C-4th-Edition/PGM148299.html
• C++ is a compiled language
  • To compile (in EOS): g++ -std=c++17 -Wall myCppFile.cpp -o myExcecutable
    • Emphasize need for -std=c++17
      • (Without it some newer language constructs – like initializer lists – won’t compile.)
    • Emphasize importance of -Wall
  • To run (in EOS): ./myExecutable
  • If you don’t specify the output with -o, a file named a.out is generated.
  • You may have at most one main function in the referenced code.
• C++ looks a lot like Java with several key differences:
  • Namespaces are always explicit. (Not implied by directory structure.) See Stroustrup Section 3.4.
  • std::cout (See Strostroup Chapter 10.)
  • Separate .h and .cpp files. (See Stroustrup Sections 3.1 and 3.2.)
  • See LawnMower.{h,cpp} and mowerUser{A,B}.cpp
  • Sample code available here: https://github.com/kurmasz-assignments/cis263-sample-code

Week 1 / Day 2

More C++

• CLion
  • From JetBrains https://www.jetbrains.com– same company as IntelliJ
  • Students have free access
  • To get started
    1. Clone the repo with the starter code.
    2. File -> New Project.
    3. Edit path to point to folder for cloned repo.
    4. Edit CMakeLists.txt
• Objects are, by default, created on the stack. (No need to use new as in Java.)
  • Draw stack diagram. (Show both local varaibles and function calls in both C++ and Java.)
• Variables are not initialized. If you declare a variable and don’t give it a value, the value will get a “random” value.
  • Show how this can happen with a stack diagram.
• By default, objects are passed by value (whereas Java objects are passed by reference). See Stroustrup Section 3.6.
  • By adding & to a type, you can pass an object by reference like Java does.
  • See Point2D.h and passByValueOrReference.cpp
  • Draw stack and memory diagram
• Pointers
  • The & operator returns an object’s memory address.
  • (The operator is also used to declare a reference type. With practice, you can tell the meaning from context. When used with a type, & means reference. When used with a value, it means address.)
  • The * operator is used to either declare or dereference a pointer. (When a pointer is dereferenced we take access the object being pointed at.)
  • See slidePointUsingPointers in passByValueOrReference.cpp.
  • Draw stack and memory diagram
  • Also used when creating objects dynamically using new (similar to Java). See MyIntVector.h
  • In general, you should use references when you can. Only use poineters when you must.
• Copy / assignment of complex objects
  • By default, objects are copied field by field.
  • This works for objects containing only simple types like Point2D.
  • It can cause problems for objects that contain pointers and other shared resources.
    • missingCopyConstructor.cpp shows what goes wrong when the default C++ copy constructor is used when a custom one is needed.
    • Draw memory diagram
    • expectedCopyBehavior demonstrates the expected behavior when a correct copy constructor is provided.
  • The assignment (i.e., = operator) must be overloaded for the same reason.
  • Warning: Sometimes the compiler will use the copy constructor when you think it might be using the assignment operator – especially when using an assignment in a declaration like MyVector v1 = v2.
  • See Stroustrup Section 5.2 for a general discussion of copy and move.
  • Weiss Section 1.5.6 goes into even more depth.
  • There is also a move operator for the special circumstance where an object is copied then destroyed.
    • Most common when returning an object from a method.
    • See Stoustrup Section 5.2.2 for details on the move operator.
    • Weiss Section 1.5.6 goes into even more depth about rvalue references.