/* * Author: Xan * Date: 18th April 2018 * * ASSIGNMENT: * * Take student grades (as counts, i.e. 20 people got grade A, 15 grade B etc * up to grade F. Then display the results in a bar graph. * * Note: This is definitely not efficient code. It's also not been tested * properly yet, and it was knocked together as a fun experiment. * So be warned before using any of this code for yourself. * * It's an ongoing project. * * KNOWN ISSUES: * * Sometimes the percentages on the text-based bar graph, won't add up to * 100 exactly. This is not a bug. It's because we are rounding up each * percentage (for each grade, A to F), to the nearest 5 percent. * 5 percent, because that's the resolution of our graph. If we were using * a standard graphical method of displaying a graph, it would be accurate. * * * USAGE: * * Enter six integers, representing how many people got grades for each grade. * i.e. enter a number of how many people got an A, then do the same for B, C, * and up to F. * * After you've entered the information, the code draws a text-based bar graph. */ import java.util.*; import java.util.Dictionary; public class GradeSystem { private Map grades; GradeSystem() { grades = new HashMap<>(); } public boolean GetGradesCountFromUser() { int gradeCount; Scanner scanner = new Scanner(System.in); System.out.println("\nPlease enter how many students got..."); for (char grade = 'A'; grade <= 'F'; grade++) { System.out.format("\ngrade %c: ", grade); if (!scanner.hasNextInt()) { System.out.println("\n\nWARNING: Please ensure you enter six integers\n\n"); return false; } else { gradeCount = scanner.nextInt(); } // Store the grade count entered by the user, for later use. grades.put(Character.toString(grade), gradeCount); } return true; } public int GetGradeCount(char grade) { return grades.get(Character.toString(grade)); } // Get the sum of all the grade counts, // i.e. if 20 people got an A, 5 people got a B, // You'd total up 20 + 5, and so on for all grades A to F. private int GetTotalGradeCount() { int totalGradeCount = 0; for (char grade = 'A'; grade <= 'F'; grade++) { totalGradeCount += GetGradeCount(grade); } return totalGradeCount; } public void DisplayBarGraph() { String[] lines = new String[23]; for (int i = 0; i <= 20; i++) { int percentage = (20 - i) * 5; lines[i] = String.format("%4d ", percentage); } lines[21] = ""; lines[22] = " % A B C D E F"; // Get the total of all the grade counts. int totalGradeCount = GetTotalGradeCount(); System.out.println(); for (char grade = 'A'; grade <= 'F'; grade++) { int gradeCount = GetGradeCount(grade); if (gradeCount < 0) { System.out.format("\nWARNING: Negative count found for grade %c, assuming zero.\n", grade); gradeCount = 0; } for (int i = 0; i <= 20; i++) { int percentage = (20 - i) * 5; // Round up grade count percentage, to nearest 5%. int roundedGradePercent = Math.round ( (float)gradeCount / (float)totalGradeCount * 100 / 5 ) * 5; if (percentage <= roundedGradePercent) { lines[i] += " ### "; } else { lines[i] += " "; } } } System.out.println("\n"); for (int i = 0; i <= 22; i++) { System.out.println(lines[i]); } } } public class Program { public static void main(String[] args) { GradeSystem gradeSystem = new GradeSystem(); if (!gradeSystem.GetGradesCountFromUser()) { } else { gradeSystem.DisplayBarGraph(); } } }

Student Grade Bar Graph