UNIVERSITY OF THE FREE STATE DEPARTMENT OF COMPUTER SCIENCE AND INFORMATICS RIS 114 CLASS TEST 2 and 3 DATE: 4 August 2014 TIME: 180 minutes MARKS: 70

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1 UNIVERSITY OF THE FREE STATE DEPARTMENT OF COMPUTER SCIENCE AND INFORMATICS RIS 114 CLASS TEST 2 and 3 DATE: 4 August 2014 TIME: 180 minutes MARKS: 70 ASSESSOR: Prof. P.J. Blignaut (+1 bonus mark) This is an open-book test Question 1 (21) Develop a Windows application as shown in the example that allows the user to guess a number (between 1 and 6, both included) that will be randomly generated by the computer. Write code for the IsHit() method that accepts the guess number as value parameter and a random number as a reference parameter, and generates a random number to compare with the guess number. The method returns true if the numbers are equal, otherwise it returns false. Write code in the event handler of the Hit_Click() button to accept the guess number from the text box and call IsHit(): If the numbers are equal display You won! message on the Message box, otherwise display the message as shown in the example. Hints: The Random class contains a method Next() that takes the lower and upper limits as parameters and returns a random number. Use the Help and Intellisense to get examples and determine the exact syntax and usage. Question 2 (18) Develop a console application that iterates through the numeric values 65 to 122 to generate character values that correspond to these numeric values as shown in the example. The numeric values and their corresponding characters from 91 to 96 must not be listed. Each row should have only 13 elements (A 65 count as a single element).

2 Question 3 Use Visio or pen and paper to develop a flowchart for the application that prints the classification of the weather conditions according to the following temperature classification: Below 15: Cold Between 15 and 28: moderate Above 28: Hot [8] Question 4 The volume of a cylinder can be calculated by using the formula: Volume= pi*radius 2 *height Create a new console application and save your program as T:\RIS114\Studentnumber_Surname_Question4.cs. Write a method GetValue. The method should display a prompt to the user to enter values between a specified minimum and maximum until the acceptable value is received. The method should have three parameters: - A string value parameter that will be used as a prompt to the user; - Two double parameters (Maximum and Minimum) that will be used to check for erroneous input. The method should return a value of type double. (14) In the Main method of your program: - Declare and initialise double variables for the Maximum and Minimum. - Declare the variables for Volume, Radius and Height. - Call the GetValue method for the Radius and Height variables. - Calculate and display the volume of the cylinder according to the above formula. Hint: You may use the System.Math.PI constant. (10) Look at the following screen print for an example. [24]

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4 Memo Question 1 (21) Form name and Text Button name and Text Text box name private void btnhit_click(object sender, EventArgs e) int gn; yn = int.parse(txtnumber.text); if (IsHit(gn, rn)) MessageBox.Show("You won!", "Guess number"); else string smsg = String.Format("You lost.\n\n My number is 0.", rn); MessageBox.Show(sMsg, "Guess number"); private bool IsHit(int gn, ref int rn) Random rd = new Random(); rn = rd.next(1, 7); return rn == gn;

5 Question 2 (18) int number_of_codes = 0; Console.Write("Letters of the alphabet with their numerical codes from 65" + "\n to 122 (Excluding special characters) are the following:\n\n"); for (int numerical_code = 65; numerical_code <= 122; numerical_code++) if (numerical_code <= 90 numerical_code >= 97) char character_to_print = (char)numerical_code; Console.Write(numerical_code.ToString() + " " + character_to_print + " "); number_of_codes++; if (number_of_codes == 13) Console.Write("\n"); number_of_codes = 0; Console.WriteLine(); Console.Write("\nPress any key to exit..."); Console.ReadKey(); //two marks for proper exit instructions

6 Question 3 (8) Start Get Temp No Temp < 15 Yes No Temp < 28 Yes Print Cold Print Hot Print Moderate Stop 0.5

7 Question 4 (24) static void Main(string[] args) double dmax = 5.0; double dmin = 0.5; double radius, height, volume; radius = GetValue("radius", dmin, dmax); Console.Write("\n\n"); height = GetValue("height", dmin, dmax); volume = Math.PI * radius * radius * height; Console.WriteLine(); Console.WriteLine("The volume of the cylinder is 0:F", volume); Console.WriteLine(); Console.Write("Press any key to exit..."); Console.ReadKey(); //One for proper exit instruction static double GetValue(string sprompt, double dmin_value, double dmax_value) double dvalue; do Console.Write("Give the " + sprompt + " of the cylinder between " + dmin_value + " and " + dmax_value + " :"); dvalue = double.parse(console.readline()); while ((dvalue < dmin_value) (dvalue > dmax_value)); return dvalue;