CS 2040 Sample Code

Ruby Examples

• return-multiple.rb: A complete Ruby program illustrating returning multiple values from a function.
• echoinput.rb: echo standard input to standard output (with line numbers); type

          ruby echoinput.rb < echoinput.rb
  

  at the command prompt (after installing Ruby) to display the program.
• sum.rb: compute sum of entered numbers. Enter

          ruby sum.rb
          5
          4
          3
          Control-Z
  

  (where the last line is holding down the control key and pressing a Z) to print a 12.
• generate.rb: generate a list of numbers, one per line:

          ruby generate.rb 20 30 3 | ruby sum.rb
          98
  

• gpa.rb: compute GPA
  • revised-gpa.rb: a version of gpa.rb that can be loaded as a part of a larger project
• countvowels.rb: Ruby code to count vowels in the input, illustrating breaking a program into multiple functions with a main.
• phones.rb: simple phone book based on arrays; to test, run irb and type

          irb> load 'phones.rb'
          irb> test_phone_book
  

• revised-phones.rb: revised phone book using hash tables.

C++ Examples

• ave.cpp: print the average of a list of integers
  ave1000.cpp: same, but using arrays; build with g++ -std=c++11 ave1000.cpp
• round_error.cpp: illustrates why == on floats is a bad idea
• simple_time.cpp: illustrates simple classes (along with cassert)
• occurrences.cpp: count number of times a character appears input. If build to a.exe, then

          a.exe < occurrences.cpp
  

  counts 17 semicolons, and

          a.exe _ < occurrences.cpp
  

  counts 5 underscores.
• increasing-numbers.cpp: illustrates writing an eof-controlled loop with limits
  • increasing-numbers-v2.cpp: Same, but using functions.
• distinct1000.cpp: count number of distinct values in the input.
• countvowels.cpp: count the number of vowels; illustrating reading input by characters (and including code to read from a file as well as standard input). This is the C++ version of countvowels.rb.
• todo.cpp: simple todo list using fixed-size arrays and strings.
• Todo lists with pointers: a more extensible version of ToDo lists, this time using pointers so each ToDo item has identity. This version also illustrates documenting classes and methods in a reasonable way.
• ave.h, ave.cpp, printave.cpp: illustrating separate compilation and reference parameters
• simple_vector.h: Simple vector code
• Time example: illustrates simple inheritance
• Account balance: computing account balances, illustrating definitions distributed over multiple files.
• alg-examp.cpp: illustrate algorithm code
• slist.cpp: Simply Linked List
• rwh_string.cpp: simple implementation of arbitrary-length strings
• list_iterator.cpp: illustrates iterating over a list
• repeated_words.cpp: illustrates using std::set

C Examples

• RPN Calculator
• Average Example, C version: a rewrite of ave.cpp
• Average of 1000 doubles, C version: a rewrite of ave1000.cpp, but this version prompts for inputs and computes the average of doubles
• array.c: illustrates properties of arrays
• points0.c, points.c: structs in C using two different styles
• messed_up.c: really odd code...
• hello.c: yup
  • See also: MysteryCode.java

Java Examples

• Display.java: illustrates reading from standard input and writing to standard output
• MysteryCode.java: illustrates that Java programs can be obfuscated as well