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copied!<p>StackOverflow community. I'm trying to create a command line application for the manipulation of X and Y coordinates. What confuses me is that when it asks for X or Y under case B, it thinks that I typed in something other than X or Y when I haven't typed in anything at all. What could be making this happen?</p> <pre><code>public class OrderedPairTest { public static void main(String[] args) { OrderedPair op1 = new OrderedPair(); OrderedPair op2 = new OrderedPair(); OrderedPair op3 = new OrderedPair(); EasyReader console = new EasyReader(); System.out.println("Ordered Pairs 1, 2, and 3 are set to (0,0).\nWhat would you like to do?"); System.out.println("Type A to display values, B for setting values, C for moving values,\nD for string conversion, E for printing, and F for other calculations."); char one = console.readChar(); switch(one){ case 'A': System.out.print("Type the ordered pair's number: "); int onea = console.readInt(); switch(onea){ case 1: op1.getX(); op1.getY(); break; case 2: op2.getX(); op2.getY(); break; case 3: op3.getX(); op3.getY(); break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } main(null); case 'B': System.out.print("Type the ordered pair's number: "); int oneb = console.readInt(); switch(oneb){ case 1: System.out.print("\nX or Y?"); char twoa = console.readChar(); switch(twoa){ case 'X': System.out.print("\nValue? "); int valx1 = console.readInt(); op1.setX(valx1); break; case 'Y': System.out.print("\nValue? "); int valy1 = console.readInt(); op1.setY(valy1); break; default: System.out.println("\nInvalid axis. Returning to the main menu."); main(null); } break; case 2: System.out.println("X or Y?"); char twob = console.readChar(); switch(twob){ case 'X': System.out.println("Value?"); int valx2 = console.readInt(); op1.setX(valx2); break; case 'Y': System.out.println("Value?"); int valy2 = console.readInt(); op1.setY(valy2); break; default: System.out.println("Invalid axis. Returning to the main menu."); main(null); } break; case 3: System.out.println("X or Y?"); char twoc = console.readChar(); switch(twoc){ case 'X': System.out.println("Value?"); int valx3 = console.readInt(); op1.setX(valx3); break; case 'Y': System.out.println("Value?"); int valy3 = console.readInt(); op1.setY(valy3); break; default: System.out.println("Invalid axis. Returning to the main menu."); main(null); } break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } main(null); case 'C': System.out.print("Type the ordered pair's number: "); int onec = console.readInt(); switch(onec){ case 1: System.out.println("X, Y or B (Both)?"); char twoa = console.readChar(); switch(twoa){ case 'X': System.out.println("Value?"); int valx1 = console.readInt(); op1.moveX(valx1); break; case 'Y': System.out.println("Value?"); int valy1 = console.readInt(); op1.moveY(valy1); break; case 'B': System.out.println("Value of X?"); int valx4 = console.readInt(); System.out.println("Value of Y?"); int valy4 = console.readInt(); op1.moveXY(valx4,valy4); break; default: System.out.println("Invalid axis. Returning to the main menu."); main(null); } break; case 2: System.out.println("X or Y?"); char twob = console.readChar(); switch(twob){ case 'X': System.out.println("Value?"); int valx5 = console.readInt(); op1.moveX(valx5); break; case 'Y': System.out.println("Value?"); int valy5 = console.readInt(); op1.moveY(valy5); break; case 'B': System.out.println("Value of X?"); int valx2 = console.readInt(); System.out.println("Value of Y?"); int valy2 = console.readInt(); op1.moveXY(valx2,valy2); break; default: System.out.println("Invalid axis. Returning to the main menu."); main(null); } break; case 3: System.out.println("X or Y?"); char twoc = console.readChar(); switch(twoc){ case 'X': System.out.println("Value?"); int valx3 = console.readInt(); op1.moveX(valx3); break; case 'Y': System.out.println("Value?"); int valy3 = console.readInt(); op1.moveY(valy3); break; case 'B': System.out.println("Value of X?"); int valx6 = console.readInt(); System.out.println("Value of Y?"); int valy6 = console.readInt(); op1.moveXY(valx6,valy6); break; default: System.out.println("Invalid axis. Returning to the main menu."); main(null); } break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } main(null); case 'D': System.out.print("Type the ordered pair's number: "); int oned = console.readInt(); switch(oned){ case 1: op1.toString(); break; case 2: op2.toString(); break; case 3: op3.toString(); break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } main(null); case 'E': System.out.print("Type the ordered pair's number: "); int onee = console.readInt(); switch(onee){ case 1: op1.printOP(); break; case 2: op2.printOP(); break; case 3: op3.printOP(); break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } main(null); case 'F': System.out.print("Type the first ordered pair's number: "); int onef = console.readInt(); System.out.print("\nType the second ordered pair's number: "); int oneg = console.readInt(); switch(onef){ case 1: switch(oneg){ case 2: op1.distance(op2); op1.midpoint(op2); break; case 3: op1.distance(op3); op1.midpoint(op3); break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } case 2: switch(oneg){ case 1: op2.distance(op1); op2.midpoint(op1); break; case 3: op2.distance(op3); op2.midpoint(op3); break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } case 3: switch(oneg){ case 1: op3.distance(op1); op3.midpoint(op1); break; case 2: op3.distance(op2); op3.midpoint(op2); break; default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } default: System.out.println("Invalid pair number. Returning to main menu."); main(null); } main(null); default: System.out.println("Invalid option. Returning to main menu."); main(null); } } } </code></pre> <p>Here is my EasyReader class for debugging purposes. It isn't mine, but it streamlines reading strings, ints, and chars:</p> <pre><code>public class EasyReader { protected String myFileName; protected BufferedReader myInFile; protected int myErrorFlags = 0; protected static final int OPENERROR = 0x0001; protected static final int CLOSEERROR = 0x0002; protected static final int READERROR = 0x0004; protected static final int EOF = 0x0100; /** * Constructor. Prepares console (System.in) for reading */ public EasyReader() { myFileName = null; myErrorFlags = 0; myInFile = new BufferedReader( new InputStreamReader(System.in), 128); } /** * Constructor. opens a file for reading * @param fileName the name or pathname of the file */ public EasyReader(String fileName) { myFileName = fileName; myErrorFlags = 0; try { myInFile = new BufferedReader(new FileReader(fileName), 1024); } catch (FileNotFoundException e) { myErrorFlags |= OPENERROR; myFileName = null; } } /** * Closes the file */ public void close() { if (myFileName == null) return; try { myInFile.close(); } catch (IOException e) { System.err.println("Error closing " + myFileName + "\n"); myErrorFlags |= CLOSEERROR; } } /** * Checks the status of the file * @return true if en error occurred opening or reading the file, * false otherwise */ public boolean bad() { return myErrorFlags != 0; } /** * Checks the EOF status of the file * @return true if EOF was encountered in the previous read * operation, false otherwise */ public boolean eof() { return (myErrorFlags & EOF) != 0; } private boolean ready() throws IOException { return myFileName == null || myInFile.ready(); } /** * Reads the next character from a file (any character including * a space or a newline character). * @return character read or <code>null</code> character * (Unicode 0) if trying to read beyond the EOF */ public char readChar() { char ch = '\u0000'; try { if (ready()) { ch = (char)myInFile.read(); } } catch (IOException e) { if (myFileName != null) System.err.println("Error reading " + myFileName + "\n"); myErrorFlags |= READERROR; } if (ch == '\u0000') myErrorFlags |= EOF; return ch; } /** * Reads from the current position in the file up to and including * the next newline character. The newline character is thrown away * @return the read string (excluding the newline character) or * null if trying to read beyond the EOF */ public String readLine() { String s = null; try { s = myInFile.readLine(); } catch (IOException e) { if (myFileName != null) System.err.println("Error reading " + myFileName + "\n"); myErrorFlags |= READERROR; } if (s == null) myErrorFlags |= EOF; return s; } /** * Skips whitespace and reads the next word (a string of consecutive * non-whitespace characters (up to but excluding the next space, * newline, etc.) * @return the read string or null if trying to read beyond the EOF */ public String readWord() { StringBuffer buffer = new StringBuffer(128); char ch = ' '; int count = 0; String s = null; try { while (ready() && Character.isWhitespace(ch)) ch = (char)myInFile.read(); while (ready() && !Character.isWhitespace(ch)) { count++; buffer.append(ch); myInFile.mark(1); ch = (char)myInFile.read(); }; if (count > 0) { myInFile.reset(); s = buffer.toString(); } else { myErrorFlags |= EOF; } } catch (IOException e) { if (myFileName != null) System.err.println("Error reading " + myFileName + "\n"); myErrorFlags |= READERROR; } return s; } /** * Reads the next integer (without validating its format) * @return the integer read or 0 if trying to read beyond the EOF */ public int readInt() { String s = readWord(); if (s != null) return Integer.parseInt(s); else return 0; } /** * Reads the next double (without validating its format) * @return the number read or 0 if trying to read beyond the EOF */ public double readDouble() { String s = readWord(); if (s != null) return Double.parseDouble(s); // in Java 1, use: return Double.valueOf(s).doubleValue(); else return 0.0; } } </code></pre> <p>And finally, here's my OrderedPair class:</p> <pre><code>public class OrderedPair { int a,b; String q = ""; public int getX() { System.out.println("X is "+a); return a; } public int getY() { System.out.println("Y is "+b); return b; } public void setX(int x) { a = x; System.out.println("X has been set to "+a); if (b != 0) setQ(); else; } public void setY(int y) { b = y; System.out.println("Y has been set to "+b); if (a != 0) setQ(); else; } public String toString() { String msg = ("("+a+","+b+") Q"+q); System.out.println("Values have been converted into string."); return msg; } public int moveX(int amt) { a+=amt; System.out.println("X has been moved "+amt+" units."); if ((b != 0) && (a != 0)) setQ(); else; return a; } public int moveY(int amt) { b+=amt; System.out.println("Y has been moved "+amt+" units."); if ((b != 0) && (a != 0)) setQ(); else; return b; } public void moveXY(int amt1, int amt2){ a+=amt1; b+=amt2; System.out.println("X has been moved "+amt1+" units."); System.out.println("Y has been moved "+amt2+" units."); if ((b != 0) && (a != 0)) setQ(); else; } public void distance(OrderedPair other) { double d = Math.sqrt(Math.pow(other.b-this.b,2)+Math.pow(other.a-this.a,2)); System.out.println("The distance between the two points is: "+d); } public void midpoint(OrderedPair other) { int x3 = (this.a+other.a)/2; int y3 = (this.b+other.b)/2; System.out.println("The midpoint is at: ("+x3+","+y3+")"); } public void printOP() { if (q!= "") System.out.println("("+a+","+b+") Q"+q); else System.out.println("Q has not been set."); } private void setQ() { if ((a!=0)&&(b!=0)){ if (a > 0){ if (b > 0) q = "I"; else q = "IV"; } else { if (b > 0) q = "II"; else q = "III"; } System.out.println("The quadrant has been set."); } else System.out.println("X and/or Y are zero, please assign the variables a nonzero value."); } } </code></pre>

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