Practical Code Formatting: C++ Basics and Examples

1. Code Formatting By: Taylor Helsper

2. Outline • Introduction • Data Types • C++ Program Structure • Formatting Basics • Examples • Conclusion • Questions

3. Introduction • What is this lecture? • Part of a CSE 4000 Independent Study Course • “Practical Issues in Software Engineering” • What’s the point? • To provide practical information to students in Software Engineering topics

4. Data Types • Int • Short for Integer • It's just a whole number • These are Ints • 10,000 • -1 • 314 • These aren't Ints • 1.1 • "HELLO" • 'f'

5. Data Types • Float / Doubles • Numbers with decimals! • What's the difference? Doubles are twice as big. • These are Floats/Doubles • 1.1 • 0.0 • 3.14159265 • These Aren't • "HELLO" • 'i'

6. Data Types • Bool • Short for Boolean • True/False • Any number != 0 equals True • These are Bools • 0 • 1 • True • False • These Aren't • 'HELLO' • 'f'

7. Data Types • Char • A single letter • These are Chars • 'p' • 'i' • ‘e' • These aren't • "Hello"

8. Data Types • String • 0 or more characters • These are strings • "I <3 Pie" • "Intermediate is the most amazing class in the history of classes" • "The internet is a series of tubes." • These aren't • 1 • 1.1 • True

9. Outline • Introduction • Data Types • C++ Program Structure • Formatting Basics • Examples • Conclusion • Questions

10. C++ Program Structure • Main Function Name of the function where C++ starts Number of arguments to the program int main(int argc, char** argv) { cout << “Hello World!”; } Strings of the arguments

11. C++ Program Structure • Arguments Example

12. C++ Function Structure • Functions Name of the function Function parameters string get_message(int a) { string s = “”; if ( a < 10 ) { s = “Less than 10”; } else { s =“>= 10”; } return s; }

13. C++ Function Examples • Good functions…

14. C++ Function Examples • … help code readability

15. Return Types • Functions are different in C++ than in Python • Return Types must be defined • Definitions look like this • The return the type must always be defined. int function_name( float arg1, bool arg2 ) { return 1; }

16. Outline • Introduction • Data Types • C++ Program Structure • Formatting Basics • Examples • Conclusion • Questions

17. Formatting Basics • Consistency • Very important for readability • Makes debugging much easier • Easier for others to review your code

18. Formatting Basics • Whitespace • Each indent should represent a new level of logic • Allows code to be read much easier

19. Formatting Basics • Good Variable Names • Name variables according to what they represent • Long variable names are good if they are helpful

20. Formatting Basics • Whitespace and Naming Example void f(int n) { int s=0; int e=1; For (int b=0;b<n;b++){ cout << e; e = s + e; s = e; }} void fib(int num) { int start=0; int end=1; for (int n=0; n<num; n++) { cout << end; end = start + end; start = end; } }

21. Formatting Basics • Comments • Help with debugging • Allow others to more easily understand the code

22. Outline • Introduction • Data Types • C++ Program Structure • Formatting Basics • Examples • Conclusion • Questions

23. Examples • Good Code • Bad Code

26. Examples codequiz.com

27. Example #1 Write a function that takes one number and returns the square of the number Ex. Input: 2; Returns 4

28. Example #2 Write a function that takes three numbers and returns the average Ex. avg(double d1, double d2, double d3)

29. Example #3 Write a function to return the area of a square. The function will take the height and width of the square as parameters.

30. Example #4 Write a function that takes a number grade and prints the associated letter grade. Ex. 95 prints “A” 80 prints “B”

31. Conclusion • Be consistent • Formatting helps you and others understand your code • Start good habits now

32. Questions?