1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332

using System; using System.Collections.Generic; using System.ComponentModel; using System.Data; using System.Drawing; using System.Linq; using System.Text; using System.Windows.Forms;   namespace NickGeorge.Cis300.Calculator {        /// <summary>        /// Main class for calculator        /// </summary>     public partial class Calculator : Form     {               /// <summary>               /// Stores total of calculator input.               /// </summary>         private Double _total = 0.0;                 /// <summary>               /// Boolean to tell if calculator is in display or input modes.               /// </summary>         private Boolean _input = false;                 /// <summary>               /// Stack of all used operators.               /// </summary>               private Stack<char> _operators = new Stack<char>();                 /// <summary>               /// Stack of all used operands.               /// </summary>               private Stack<double> _operands = new Stack<double>();                 /// <summary>               /// Method which intializes GUI               /// </summary>         public Calculator()         {             InitializeComponent();         }                 /// <summary>               /// Method which appends given text/integer to display and stores the current value if necessary               /// </summary>               /// <param name="str">Input string to append to the display</param>         private void AppendTo(String str)         {                      if(this._input)                             this.uxSum.Text = this.uxSum.Text + str;                      else                      {                             this._input = true;                             this.uxSum.Text = str;                      }         }                 /// <summary>               /// Returns the precedence of given operator               /// </summary>               /// <param name="c">Operator</param>               /// <returns>Int value of precedence 0-2</returns>               private int GetPrecedence(char c)               {                      switch(c)                      {                             case '*':                             case '/':                                    return 2;                               case '+':                             case '-':                                    return 1;                               default:                                    return 0;                      }               }                 /// <summary>               /// Will record an arithmatic sequence.               /// </summary>               /// <param name="Operator">Operator of the sequence</param>               /// <param name="Operand">First value of the sequence</param>               private void StartSequence(char Operator, double Operand)               {                      this._input = false;                      this._operands.Push(Operand);                      this._operators.Push(Operator);                      this.uxSum.Text = Operand.ToString();               }                 /// <summary>               /// Performs all of the pending operations up to, but not including, the most recent pending operation having precedence less than or equal to a given precedence               /// </summary>               /// <param name="precedence">value of precedence at which to stop calculating</param>               /// <param name="operand">Last pending operand to use in calculation</param>               /// <returns>Value of calcuation</returns>               private double Calculate(int precedence, double operand)               {                      double total = operand;                        while(this._operators.Count > 0 && this.GetPrecedence(this._operators.Peek()) > (precedence - 1))                      {                                                                switch (this._operators.Pop())                             {                                    case '+':                                           total += this._operands.Pop();                                           break;                                      case '-':                                           total = this._operands.Pop() - total;                                           break;                                      case '*':                                           total *= this._operands.Pop();                                           break;                                      case '/':                                           total = this._operands.Pop() / total;                                           break;                             }                      }                        return total;               }                 /// <summary>               /// Clears totals and sets display to "0"               /// </summary>         private void uxClear_Click(object sender, EventArgs e)         {             this._total = 0.0;             this.uxSum.Text = "0";                      this._operands.Clear();                      this._operators.Clear();             this._input = false;         }                 /// <summary>               /// Adds 0 to display               /// </summary>         private void uxZero_Click(object sender, EventArgs e)         {                      AppendTo("0");         }                 /// <summary>               /// Adds 1 to display               /// </summary>               private void uxOne_Click(object sender, EventArgs e)               {                      AppendTo("1");               }                 /// <summary>               /// Adds 2 to display               /// </summary>               private void uxTwo_Click(object sender, EventArgs e)               {                      AppendTo("2");               }                 /// <summary>               /// Adds 3 to display               /// </summary>               private void uxThree_Click(object sender, EventArgs e)               {                      AppendTo("3");               }                 /// <summary>               /// Adds 4 to display               /// </summary>               private void uxFour_Click(object sender, EventArgs e)               {                      AppendTo("4");               }                 /// <summary>               /// Adds 5 to display               /// </summary>               private void uxFive_Click(object sender, EventArgs e)               {                      AppendTo("5");               }                 /// <summary>               /// Adds 6 to display               /// </summary>               private void uxSix_Click(object sender, EventArgs e)               {                      AppendTo("6");               }                 /// <summary>               /// Adds 7 to display               /// </summary>               private void uxSeven_Click(object sender, EventArgs e)               {                      AppendTo("7");               }                 /// <summary>               /// Adds 8 to display               /// </summary>               private void uxEight_Click(object sender, EventArgs e)               {                      AppendTo("8");               }                 /// <summary>               /// Adds 9 to display               /// </summary>               private void uxNine_Click(object sender, EventArgs e)               {                      AppendTo("9");               }                 /// <summary>               /// If in input mode, will invert the sign associated with the current value               /// </summary>               private void uxInvert_Click(object sender, EventArgs e)               {                      if(this._input)                      {                             if(this.uxSum.Text.CompareTo("0") != 0)                             {                                    if(this.uxSum.Text.Contains("-"))                                           this.uxSum.Text = this.uxSum.Text.Substring(1);                                    else                                           this.uxSum.Text = "-" + this.uxSum.Text;                             }                      }               }                 /// <summary>               /// If in input mode, will add a decimal to the current value               /// </summary>               private void uxDecimal_Click(object sender, EventArgs e)               {                      if (!this._input)                      {                             this._input = true;                             this._total = Double.Parse(this.uxSum.Text);                             this.uxSum.Text = "0.";                      }                      else                      {                             if (!this.uxSum.Text.Contains('.'))                                    this.uxSum.Text = this.uxSum.Text + ".";                      }               }                 /// <summary>               /// If two values are given, will operate the two values together to a new value               /// </summary>               private void uxEqual_Click(object sender, EventArgs e)               {                      this._input = false;                      double output = Double.Parse(this.uxSum.Text);                      while(this._operands.Count > 0)                             output = this.CloseParenth(output);                      this.uxSum.Text = output.ToString();               }                 /// <summary>               /// Creates an addition sequence               /// </summary>               private void uxAdd_Click(object sender, EventArgs e)               {                      this.StartSequence('+', this.Calculate(this.GetPrecedence('+'), Double.Parse(this.uxSum.Text)));               }                 /// <summary>               /// Creates a subtration sequence               /// </summary>               private void uxSubtract_Click(object sender, EventArgs e)               {                      this.StartSequence('-', this.Calculate(this.GetPrecedence('-'), Double.Parse(this.uxSum.Text)));               }                 /// <summary>               /// Creates a multiplication sequence               /// </summary>               private void uxMultiply_Click(object sender, EventArgs e)               {                      this.StartSequence('*', this.Calculate(this.GetPrecedence('*'), Double.Parse(this.uxSum.Text)));               }                 /// <summary>               /// Creates a division sequence               /// </summary>               private void uxDivide_Click(object sender, EventArgs e)               {                      this.StartSequence('/', this.Calculate(this.GetPrecedence('/'), Double.Parse(this.uxSum.Text)));               }                 /// <summary>               /// Creates a open parenthesis to the order of operations               /// </summary>               private void uxOpenParenth_Click(object sender, EventArgs e)               {                      this._input = false;                      this._operators.Push('(');               }                 /// <summary>               /// Creates a close parenthesis to the order of operations               /// </summary>               private void uxCloseParenth_Click(object sender, EventArgs e)               {                      this._input = false;                      this.uxSum.Text = this.CloseParenth(Double.Parse(this.uxSum.Text)).ToString();               }                 /// <summary>               /// Will close a set of parenthesis               /// </summary>               /// <param name="op">Current input</param>               /// <returns>Calculated number</returns>               private double CloseParenth(double op)               {                      double number = this.Calculate(this.GetPrecedence('('), op);                      if (this._operators.Count > 0)                             this._operators.Pop();                      return number;               }     } }