CS 160, Spring 2015
Programming Quiz Q5
Practice Programming Quiz

• You CANNOT use any outside resources
  - This includes the internet, past recitations or programs, textbooks, notes, friends, enemies, classmates, cell phones, tablets, laptops, etc.
• Any and all questions should be directed to your TA and your TA's helper.
• This is a practice quiz copied from the final programming quiz last semester.

Setup

1. Create a project called Q5 in Eclipse.
2. Create a class called Q5 in the project Q5 with a main method.
3. Download QuizInterface.java to the source (workspace/Q5/src) directory.
4. Download input.txt to the project (workspace/Q5) directory.
5. Make your Q5 class implement this interface.
6. Use Eclipse to add empty methods for all the methods required in the interface.

7. Create the following public static class variables.

   • An integer called numberLines to store the line count.
   • An integer called numberChars to store the character count.
   • An integer called numberLetters to store the letter count.
   • An integer called numberDigits to store the digits count.
   • An array of strings called fileContents to store the file contents.
   • An array of doubles called testArray to store some numbers.
   
   
8. Initialize all integer counters to zero when they are declared.
9. Allocate and initialize testArray with the values: 92.2, 45.9, 16.4, 31.2, 67.8, 95.0, 71.1.
10. Do not allocate or initialize the fileContents array.

Instructions for each method:

1. readFile
• This method has a single parameter, which is the name of the file.
• The purpose of this method is to read the contents of the file into an array.
• You must use a try/catch block and a Scanner object.
• The first line of the file has an integer that specifies the number of lines.
• Read this value into the variable numberLines.
• Call nextLine again to discard the rest of the line!
• Allocate the fileContents array to have numberLines elements.
• Write a for loop that reads the specified number of lines into fileContents.
• The catch exception code should do nothing.


2. computeStatistics
• This method takes an array of Strings as a parameter and has no return value.
• The purpose of this method is to count all the characters in an array of strings.
• Count the number of characters in the array and assign to numberChars.
• Count the number of letters in the array and assign to numberLetters.
• Count the number of digits in the array and assign to numberDigits.
• Do not use fileContents in this method, instead count characters in the array passed in.


3. printStatistics
• This method has no parameters and no return value.
• The purpose of this method is to print the statistics to the console.
• Here is example output from this method for a different input file:

  		Number of lines: 10
  		Number of characters: 182
  		Number of letters: 145
  		Number of digits: 19
  	

• Match capitalization, spelling, and white space exactly!


4. writeFile
• This method has two parameters, the file name and an array of strings.
• The purpose of this method is to write a file.
• You must use a try/catch block and a PrintWriter object.
• Write a for loop that writes each element in the array to a separate line in the file.
• Precede each line by a line number followed by a colon and a space.
• The line numbers should start at one (not zero).
• The catch exception code should do nothing.
• Here is example of the format of the file contents:

  	1: First element of the array
  	2: Second element of the array
  	3: Third element of the array
  	...
  	

5. findLargest
• This method takes an array of doubles as a parameter and has a single return value of type double.
• The purpose of this method is to find the largest element in the array.
• Iterate the array and find the largest value, then return it.
• You do not have to handle an empty array.

TESTING: Test your methods by creating a Q5 object and using it to call each method, for example:

	Q5 q = new Q5();
	q.readFile(args[0]);
	q.computeStatistics(fileContents);
	q.printStatistics();
	q.writeFile(args[1], fileContents);
		
	System.out.println("Array = " + Arrays.toString(testArray));
	System.out.println("Largest value = " + q.findLargest(testArray));