OldTexasCode

Old Texas Code

Java Coding Samples

Various Java programs to illustrate various concepts from an old CS course at UTexas.edu. This java code is from the last century.

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• A Hello World! Java program.

• Calling Methods. A sample of how to call methods in the same class.

• For loop. A simple example of using for loops to calculate factorial. Uses the built in int data type so only good to 13!

• Enhanced for loop

• Value Parameters: An example that shows the behavior of value parameters. In Java all parameters are passed by value. 

• String Example. A few brief examples of String manipulations.

• BinaryConverter. A program with examples of various Java syntax that converts a base 10 int to base 2 String.

• PrimeEx A program with various approaches to determine if an int is prime or not. Used to demonstrate Java syntax. You need the Stopwatch class, a non standard Java class, as well.

• Pointers as Value parameters

• Array Examples

• 2D array Example. A simplified version of filtering a picture represented by ints.

• 2D array example. Very simple version of the Conway's Game of Life.

• Getting input from Keyboard with Scanner class

• Reading ints from file with Scanner class

• Writing ints to file

• Connecting to and reading from a web page.

• Program to create ASCII frequency table from file and url. Demonstration of try / catch blocks. The CIA 2008 Factbook may be downloaded from Project Gutenberg.

• IntListVer1 First version of the IntList class developed in class. Developing class to illustrate various class design and implementation issues in Java.

• IntListTesterVer1

• IntListVer2 Added default add method, equals method, and toString methods. Includes versions of toString using String concatenation and StringBuffer to illustarte performance differences.

• IntListTesterVer2

• IntListVer3. Added insert and remove methods.

• SortedIntList. Inherits from InListVer3 to create a SortedIntList. Class is "broken" because random insertions still allowed.

• GenericList. Altered the list to store anything, not just ints.

• Die class. A class that models a playing die.

• DemoClass: This illustrates some of the more confusing concepts in class syntax and mechanics such as constructors, static vs. instance methods, and method overloading. 

• Stopwatch class. A class for measuring how long it takes for a program to run.

  • Documentation for Stopwatch class.
    

• Create a Set. A method that using polymorphism to create a set from an array.

• Recursion examples. Includes examples on finding space taken up by files in a directory including all files in all subdirectories, recursive factorial, recursive power, recursive Fibonacci numbers, and a simple knapsack problem.

• Eight Queens example. Code to find a a solution to an N queens problem. Note the queensAreSafe method has not been completed.

• Airlines example. Determine if airlines can be moved from airline to another based on network of airline partners. Here is a sample input file.

• Minesweeper. Another example of recursion from the game minesweeper.

• GenericListVersion2. Changed the GenericList class so that it implements the Iterable interface in order to demonstrate how to implement an iterator using an inner class.

• GenericListVersion3. Changed GenericList so it is generic based on Java generics syntax instead of relying on Object.

• ListNode. A singly linked node class used to build linked lists

• IList. A simple list interface

• LinkedList. Similar to the LinkedList developed in class. Does not contain all the methods you would expect of a LinkedList. Also implements the iterator remove method in O(N) time. An O(1) time remove method is possible.

• UnsortedHashSet - An unsorted set that uses a hashtable with closed address hashing to store values. Currently only the add method is implemented.

• UnsortedSetTest - A method to compare Java's TreeSet and HashSet to the BianrySearchTree, UnsortedSet, and UnsortedHashSet classes developed in class. Note you need a lot of other files for this to work.

• SimpleWordCount - Program demonstrating use of a map to count the frequency of words in a file.

• WordCount - Program  that compares counting words in files using an ArrayList and a Map.