一、應用介紹

安卓計算器：
實現功能：
（1）能實現基本的加減乘除運算、回退和清空輸入。
（2）豎屏時能實現基本的加減乘除運算、回退和清空輸入。橫屏時變為科學計算器，實現函數計算、進制換算等功能。
（3）數字按鍵依照電話撥號鍵盤順序排列。
（4）點擊菜單可對計算器相關特性進行配置。
（5）輸入計算公式，按等號鍵輸出計算結果。
（6）公式輸入和結果顯示區應支持長按彈出復制、粘貼功能。
（7）使用計算器過程中應不彈出軟鍵盤。
（8）可以通過進度條實時調整計算結果保留的小數點后位數，或者通過音量鍵完成同樣的效果。
（9）實現附加功能：三角函數、階乘、XY、√(Y&X)及括號，如sin(90)。
（10）輸入表達式按優先級計算，按等號輸出結果。
（11）對常用鍵布局需考慮特殊處理。
（12）處理精度和容錯問題：
a.1/3+1/3+1/3；
2.1+0.001；
1.1-1.001；
1/0、1/(1-1)和1/sin(0)等;
3/2;
對有附加功能的需要處理特殊值，如：√(2&-1) 等。

二、 運行截圖

豎屏時

橫屏時

主要代碼
MainActivity.java

public class MainActivity extends AppCompatActivity {String formula = "";//公式方程Boolean zeroMark = true; //允許輸入一個0Boolean zeroCon = false;//允許持續輸入0Boolean docMark = true;// . 可以輸入 .Boolean resultMark = false; //結果是否計算出Boolean transformMark = false; //是否進行二進制轉化Boolean errorMark = false;Boolean numAndOpMark = true;int color = 0xffffffff;private static final String REGEX = "^\\d+$";//all is numint precision = 3; //保留小數點位數@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);setRequestedOrientation(ActivityInfo.SCREEN_ORIENTATION_FULL_SENSOR); //屏幕旋轉setContentView(R.layout.col);EditText show = findViewById(R.id.show);show.setText("");show.setSelectAllOnFocus(true); // 設置長按時選擇全部calculator();}public void calculator() {disableShowInput(); // 不讓彈出軟鍵盤EditText show = findViewById(R.id.show);Button dot = findViewById(R.id.dot);Button zero = findViewById(R.id.zero);Button one = findViewById(R.id.one);Button two = findViewById(R.id.two);Button three = findViewById(R.id.three);Button four = findViewById(R.id.four);Button five = findViewById(R.id.five);Button six = findViewById(R.id.six);Button seven = findViewById(R.id.seven);Button eight = findViewById(R.id.eight);Button nine = findViewById(R.id.nine);Button add = findViewById(R.id.add);Button sub = findViewById(R.id.sub);Button division = findViewById(R.id.division);Button back = findViewById(R.id.back);Button AC = findViewById(R.id.AC);Button mul = findViewById(R.id.mul);Button eval = findViewById(R.id.eval);Button percent = findViewById(R.id.percent);Button sin = findViewById(R.id.sin);Button power = findViewById(R.id.power);Button factorial = findViewById(R.id.factorial); //階乘Button square = findViewById(R.id.square); //開根號Button brackets = findViewById(R.id.brackets);Button transform = findViewById(R.id.transform);dot.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum(".");}});zero.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("0");}});one.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("1");}});two.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("2");}});three.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("3");}});four.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("4");}});five.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("5");}});six.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("6");}});seven.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("7");}});eight.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("8");}});nine.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doNum("9");}});add.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("+");}});sub.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("-");}});mul.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("×");}});division.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {doOp("÷");}});AC.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {reSetStatus();show.setText("");}});back.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (formula.length() > 0) {if (!formula.contains("(D->B)")) {if (lastStr().equals(".")) {docMark = true;}formula = formula.substring(0, formula.length() - 1);} else {formula = formula.replace("(D->B)", "");numAndOpMark = true;transformMark = false;}show.setText(formula);show.setTextColor(0xff000000);}}});eval.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {try {String result = "";if (transformMark) { // 先判斷是不是要進行二進制轉化doTransform();return;}delLastOp(); // 如果式子是 4- 進行計算,我們打算將-號去掉,結果為4try {result = Result.getRes(formula) + ""; //將計算式放入getRes函數中進行計算} catch (Exception e) {show.setText(e.getMessage()); //getRes中拋出的異常進行抓取并顯示show.setTextColor(0xffff0000);errorMark = true;return;}System.out.println(result + "result");if (result.contains("E") && !result.contains("E-")) {// 結果使用了科學計數法表示,我們要根據情況進行處理show.setText(result);Toast toast = Toast.makeText(getApplicationContext(), "數值太大,已用科學計數法表示", Toast.LENGTH_SHORT);toast.show();return;} // String intPart;// if (result.length() > 12) {if (result.contains("E-")) {BigDecimal decimal = new BigDecimal(result);result = decimal.toPlainString();}if (result.length() > 12){result = result.substring(0, 11);}result = doPrecision(result); //進行精讀修改show.setText(result);reSetStatus();formula = result;resultMark = true;docMark = true;} catch (Exception e) {e.printStackTrace();}}});percent.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (formula.length() > 0) {if (!numAndOpMark) {return;}formula = "(" + formula + ")*0.01";try {show.setText(doEval(formula));formula = doEval(formula);} catch (Exception e) {show.setText(e.getMessage());}}}});sin.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}formula = formula + "sin(";show.setText(formula);}});square.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}formula = formula + "v(";show.setText(formula);}});power.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}formula = formula + "^";show.setText(formula);}});factorial.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}try {if (formula.contains(".") ){Toast toast = Toast.makeText(getApplicationContext(), "小數不可以階乘", Toast.LENGTH_SHORT);toast.show();return;}if (Result.getRes(formula) < 171) {formula = formula + "!";show.setText(formula);} else {Toast toast = Toast.makeText(getApplicationContext(), "數值太大!", Toast.LENGTH_SHORT);toast.show();show.setTextColor(0xffff0000);resultMark = true;}} catch (Exception e) {e.printStackTrace();}}});brackets.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (!numAndOpMark) {return;}if (lastIsNum() || lastStr().equals(")")) {formula = formula + ")";} else {formula = formula + "(";}show.setText(formula);}});transform.setOnClickListener(new View.OnClickListener() {@Overridepublic void onClick(View v) {if (formula.matches(REGEX)) {formula = formula + "(D->B)";show.setText(formula);transformMark = true;numAndOpMark = false;}}});}public String doPrecision(String result) {System.out.println(result + "rep");String tail = result.split("\\.")[1];String pre = result.split("\\.")[0];int deltaPre = precision - tail.length();if (deltaPre > 0) {for (int i = 0; i < deltaPre; i++) {result = result + "0";}} else if (deltaPre < 0) {double doubleResult = Double.parseDouble(result);BigDecimal bigResult = new BigDecimal(doubleResult);result = bigResult.setScale(precision, BigDecimal.ROUND_HALF_UP).toString();}System.out.println(result + "pre");return result;}public void reSetStatus() { //將各個監控狀態設為初始狀態EditText show = findViewById(R.id.show);show.setTextColor(0xff000000);formula = "";zeroMark = true;zeroCon = false;docMark = true;resultMark = false;transformMark = false;numAndOpMark = true;}@SuppressLint("SetTextI18n")public void doTransform() { //二進制轉化方法EditText show = findViewById(R.id.show);transformMark = false;String num = formula.split("\\(")[0];show.setText(Integer.toBinaryString(Integer.parseInt(num)) + "B");resultMark = true;docMark = true;}public String lastStr() {if (formula.length() > 0) {return formula.charAt(formula.length() - 1) + "";} else {return "";}} //返回字符的最后一個字符public String doEval(String formula) throws Exception { //做簡單的計算方法ScriptEngineManager manager = new ScriptEngineManager();ScriptEngine se = manager.getEngineByName("js");return se.eval(formula) + "";}public Boolean lastIsNum() { //最后一位是不是數字if (formula.length() == 0) {return false;} else {char lastChar = formula.charAt(formula.length() - 1);return lastChar > 47 && lastChar < 58;}}public Boolean lastIsOp() { //最后一位字符是不是操作符return isOp(lastStr());}public Boolean isOp(String str) { //傳遞的參數是不是操作符return (str.equals("+") || str.equals("×")|| str.equals("÷") || str.equals("-"));}public void doNum(String num) {EditText show = findViewById(R.id.show);show.setTextColor(0xff000000);int length = formula.length();if (!numAndOpMark) { //當使用(D->B)后我們不再允許進行任何符號的輸入return;}if (errorMark) { //是否出錯reSetStatus();errorMark = false;}if (resultMark) { //結果是否已算出formula = "";resultMark = false;}if (num.equals(".")) { //輸的字符是不是點 .000000000000if (docMark) { // && !isOp(lastStr())formula = formula + '.';show.setText(formula);docMark = false;zeroCon = true;}return;}if (num.equals("0")) { //是不是0? 00000000000if (zeroCon || zeroMark) {formula = formula + '0';}show.setText(formula);zeroMark = false;return;}if (formula.startsWith("0") && length == 1) { //0的特殊情況 09 -> 9formula = "";}if (length > 2 && formula.endsWith("0") && isOp(formula.charAt(length - 2) + "")) {formula = formula.substring(0, length - 1); // 0的特殊情況 23 + 09 -> 23 + 9}formula = formula + num; //加入計算式zeroCon = true;show.setText(formula);}public void doOp(String op) {EditText show = findViewById(R.id.show);show.setTextColor(0xff000000);if (!numAndOpMark || lastStr().equals(".")) {return;}if (errorMark) { //是否有錯誤 - is okreSetStatus();errorMark = false;}if (resultMark) { //結果是否計算出formula = show.getText().toString();resultMark = false;}if ((lastStr().equals("÷") || lastStr().equals("×")) && op.equals("-")) {addOp(op);return;}if (formula.contains("×-") || formula.contains("÷-")) {formula = formula.substring(0, formula.length() - 2);}if (formula.length() == 1 && lastStr().equals("-")) { // 只有一個減號,不允許輸任何操作符return;}if (formula.length() == 0 || lastStr().equals("(")) { //1+(?=-if (op.equals("-")) { // 第一個輸入的字符是不是-addOp(op);}return;}if (lastIsOp() && formula.length() > 0) { //若最后一個字符已經時操作符,那要替換掉舊的替換符formula = formula.substring(0, formula.length() - 1);}addOp(op); //如果沒有以上特殊情況,則加到計算式里}public void addOp(String op) { // 輸入操作符時大部分的重復工作進行封裝EditText show = findViewById(R.id.show);formula = formula + op;docMark = true;zeroMark = true;zeroCon = false;show.setText(formula);}//==================================================================================@SuppressLint("SetTextI18n")@Overridepublic boolean onKeyDown(int keyCode, KeyEvent event) { //設置精度(通過音量鍵)TextView info = findViewById(R.id.info);switch (keyCode) {case KeyEvent.KEYCODE_VOLUME_DOWN:if (precision > 1) {precision--;info.setText("保留" + precision + "位");Toast.makeText(this, "保留" + precision + "位", Toast.LENGTH_SHORT).show();} else {Toast.makeText(this, "至少保留1位", Toast.LENGTH_SHORT).show();}break;case KeyEvent.KEYCODE_VOLUME_UP:if (precision < 10) {precision++;Toast.makeText(this, "保留" + precision + "位", Toast.LENGTH_SHORT).show();info.setText("保留" + precision + "位");} else {Toast.makeText(this, "至多保留10位", Toast.LENGTH_SHORT).show();}break;}return super.onKeyDown(keyCode, event);}@SuppressLint("SetTextI18n")@Overridepublic void onConfigurationChanged(Configuration newConfig) { //橫豎屏切換時進行設置@SuppressLint("CutPasteId") EditText show1 = findViewById(R.id.show);color = show1.getCurrentTextColor();formula = show1.getText().toString(); //如果你是復制進去的式子,那必須先從show中得到式子// TODO Auto-generated method stubsuper.onConfigurationChanged(newConfig);//啟動時默認是豎屏if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_PORTRAIT) {setContentView(R.layout.col);@SuppressLint("CutPasteId") EditText show = findViewById(R.id.show);show.setText(formula);show.setTextColor(color);calculator();}//切換就是橫屏else if (getResources().getConfiguration().orientation == Configuration.ORIENTATION_LANDSCAPE) {setContentView(R.layout.row);@SuppressLint("CutPasteId") EditText show = findViewById(R.id.show);TextView info = findViewById(R.id.info);info.setText("保留" + precision + "位");show.setText(formula);show.setTextColor(color);calculator();}}//========================================================================================@Overridepublic boolean onCreateOptionsMenu(Menu menu) { //生成菜單項MenuInflater inflater = new MenuInflater(this);inflater.inflate(R.menu.menu, menu);return super.onCreateOptionsMenu(menu);}@SuppressLint("NonConstantResourceId")@Override //菜單項無所謂public boolean onOptionsItemSelected(MenuItem item) {EditText show = findViewById(R.id.show);//先判斷點擊的是哪個idswitch (item.getItemId()) {case R.id.font_10:show.setTextSize(10 * 2);break;case R.id.font_12:show.setTextSize(12 * 2);break;case R.id.font_14:show.setTextSize(14 * 2);break;case R.id.font_16:show.setTextSize(16 * 2);break;case R.id.font_18:show.setTextSize(18 * 2);break;case R.id.blue:show.setTextColor(Color.BLUE);break;case R.id.red:show.setTextColor(Color.RED);break;case R.id.green:show.setTextColor(Color.GREEN);break;}return super.onOptionsItemSelected(item);}//======================================================================================public void disableShowInput() { //設置鍵盤不可見EditText show = findViewById(R.id.show);Class<EditText> cls = EditText.class;Method method;try {method = cls.getMethod("setShowSoftInputOnFocus", boolean.class);method.setAccessible(true);method.invoke(show, false);} catch (Exception e) {//TODO: handle exception}try {method = cls.getMethod("setSoftInputShownOnFocus", boolean.class);method.setAccessible(true);method.invoke(show, false);} catch (Exception e) {//TODO: handle exception}}//=============================================================================public void delLastOp() { //寫個小遞歸,后來想想好像用不到,但懶得改了if (isOp(formula.charAt(formula.length() - 1) + "") || lastStr().equals(".")) {formula = formula.substring(0, formula.length() - 1);delLastOp();}}

ArrayStack.java

class ArrayStack {private int maxSize; // 棧的大小private double[] stack; // 數組，數組模擬棧，數據就放在該數組private int top = -1;// top表示棧頂，初始化為-1//構造器public ArrayStack(int maxSize) {this.maxSize = maxSize;stack = new double[this.maxSize];}//增加一個方法，可以返回當前棧頂的值, 但是不是真正的poppublic double peek() {return stack[top];}//棧滿public boolean isFull() {return top == maxSize - 1;}//棧空public boolean isEmpty() {return top == -1;}//入棧-pushpublic void push(double value) {//先判斷棧是否滿if (isFull()) {System.out.println("表達式錯誤");return;}top++;stack[top] = value;}//出棧-pop, 將棧頂的數據返回public double pop() {//先判斷棧是否空if (isEmpty()) {//拋出異常throw new RuntimeException("表達式錯誤");}double value = stack[top];top--;return value;}//顯示棧的情況[遍歷棧]， 遍歷時，需要從棧頂開始顯示數據public void list() {if (isEmpty()) {System.out.println("表達式錯誤");return;}//需要從棧頂開始顯示數據for (int i = top; i >= 0; i--) {System.out.printf("stack[%d]=%d\n", i, stack[i]);}}//返回運算符的優先級，優先級是程序員來確定, 優先級使用數字表示//數字越大，則優先級就越高.public int priority(int oper) {if (oper == '*' || oper == '/') {return 1;} else if (oper == '+' || oper == '-') {return 0;} else if (oper == '^'||oper == '#') {return 2;} else if (oper == '!' || oper == 'v' || oper == '%') {return 3;} else if (oper == 's' || oper == 't' || oper == 'c') {return 4;} else {return -1; // 假定目前的表達式只有 +, - , * , /}}//判斷是不是一個運算符public boolean isNum(char val) {return '0' <= val && val <= '9';}//判斷是不是一個運算符public boolean isOper(char val) {return val == '+' || val == '-' || val == '*' || val == '/' || val == '#' || val == '^' || val == '%' || val == 's' || val == 'c' || val == 't' || val == '!' || val == 'v';}//判斷是不是 (public boolean isLeftBrackets(char val) {return val == '(';}//判斷是不是 )public boolean isRightBrackets(char val) {return val == ')';}//判斷是不是 .public boolean isPoint(char val) {return val == '.';}//判斷是不是 (public boolean isTrigonometric(char val) {return val == 's';}//計算方法public double cal(double num1, double num2, int oper) {double res = 0; // res 用于存放計算的結果switch (oper) {case '+':res = num1 + num2;break;case '-':res = sub(num2,num1);// 注意順序break;case '*':res = num1 * num2;break;case '/':if (num1 == 0) {throw new RuntimeException("定義域錯誤");}res = num2 / num1;break;case '^':res = Math.pow(num2, num1);break;default:break;}return res;}/*** 三角函數運算、階乘運算或者是開根操作** @param num1* @param oper* @return*/public double mixedOperation(double num1, int oper) {double res = 1; // res 用于存放計算的結果switch (oper) {case 's':res = Math.sin(num1 * Math.PI / 180);break;case 'c':res = Math.cos(num1 * Math.PI / 180);break;case 't':res = Math.tan(num1 * Math.PI / 180);break;case '!':for (int i = 1; i <= num1; i++) {res *= i;}break;case 'v':if (num1 < 0) {throw new RuntimeException("定義域錯誤");}res = Math.sqrt(num1);break;case '%':res = num1 / 100;break;case '#':res = -num1;break;default:break;}return res;}double sub(double x, double y) {BigDecimal initResult = new BigDecimal(x - y); //計算初步結果String temp = initResult.toString();if (temp.contains(".")){temp = temp + "00000000000000000000";}else {temp = temp + ".00000000000000000000";}int lengthOfInt = getLengthOfInt(x, y); //結果整形位數int lengthOfDec = Math.max(getLengthOfDecimal(x), getLengthOfDecimal(y));int count = lengthOfInt + lengthOfDec + 2; //最后輸出的位數 = 整形位數+小數位數+小數點位數+1(四舍五入舍去)double tempResult = Double.parseDouble(temp.substring(0, count)); //將String轉換成double,并截取多一位用于四舍五入double power = Math.pow(10, lengthOfDec); //求10的幾次方用來四舍五入double finalResult = (double) (Math.round(tempResult * power)) / power; //四舍五入Log.i("result", x + "-" + y + "=" + finalResult);//此處的長度取決于小數點后面位數大的return finalResult;}int getLengthOfInt(double x, double y) {int lengthOfInt;int intX = (int) x; //x的整數部分int intY = (int) y; //y的整數部分lengthOfInt = String.valueOf(intX - intY).length(); //結果整形部分的位數 = 相減后整形的位數return lengthOfInt;}int getLengthOfDecimal(double x) {return String.valueOf(x).split("\\.")[1].length(); //計算x小數點后面的位數} public class Result {public static double getRes(String expression) {System.out.println(expression.length());expression = expression.replace("sin", "s");expression = expression.replace("÷", "/");expression = expression.replace("×", "*");ArrayStack stack=new ArrayStack(20);String exp = "";int count = 0;char[] chars = expression.toCharArray();while (count < chars.length) {if (count == 0 && chars[count] == '-') {chars[count] = '#';}if (count >= 1 && chars[count] == '-' && chars[count - 1] == '(') {chars[count] = '#';}if (count >= 1 && chars[count] == '-' && stack.priority(chars[count-1])>stack.priority(chars[count])) {chars[count] = '#';}exp += chars[count];count++;}expression=exp;//創建兩個棧，數棧，一個符號棧ArrayStack numStack = new ArrayStack(20);ArrayStack operatorStack = new ArrayStack(20);//定義需要的相關變量int index = 0;//用于掃描double num1 = 0;double num2 = 0;int oper = 0;double res = 0;char ch = ' '; //將每次掃描得到char保存到chString keepNum = ""; //用于拼接 多位數//開始while循環的掃描expressionwhile (true) {//依次得到expression 的每一個字符ch = expression.substring(index, index + 1).charAt(0);//判斷ch是什么，然后做相應的處理if (operatorStack.isLeftBrackets(ch)) { //如果是左括號//直接入符號棧..operatorStack.push(ch);} else if (operatorStack.isRightBrackets(ch)) { //如果是右括號while (operatorStack.peek() != '(') { //循環直到能夠到達 '(' 處oper = (int) operatorStack.pop();if (oper == 's' ||oper == '!' ||oper == 'v' ||oper == '#' ||oper == '%') { //如果棧頂為三角函數、階乘或者是開根num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);//把運算的結果如數棧numStack.push(res);} else {num1 = numStack.pop();num2 = numStack.pop();res = operatorStack.cal(num1, num2, oper);//把運算的結果如數棧numStack.push(res);}}//然后將當前棧頂的操作符出符號棧----其實也就是 '(' 出棧operatorStack.pop();} else if (operatorStack.isOper(ch)) { //如果是運算符if (operatorStack.isEmpty() || operatorStack.peek() == '(') {//如果符號棧為空，或者棧頂為'('operatorStack.push(ch);} else if (operatorStack.priority(ch) > operatorStack.priority((int) operatorStack.peek())) {//如果當前優先級比棧頂優先級高，直接入符號棧.operatorStack.push(ch);} else {while (!operatorStack.isEmpty() &&(operatorStack.priority(ch) <= operatorStack.priority((int) operatorStack.peek()))) {oper = (int) operatorStack.pop();if (!operatorStack.isEmpty() && (operatorStack.peek() == '!' ||operatorStack.peek() == 's' ||operatorStack.peek() == 'v' ||operatorStack.peek() == '#' ||operatorStack.peek() == '%')) {num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);numStack.push(res);//入棧} else {if (oper == 's' ||oper == '!' ||oper == 'v' ||oper == '#' ||oper == '%') { //如果棧頂為三角函數、階乘或者是開根num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);//把運算的結果如數棧numStack.push(res);} else {num1 = numStack.pop();num2 = numStack.pop();res = numStack.cal(num1, num2, oper);//把運算的結果如數棧numStack.push(res);}}}//然后將當前的操作符入符號棧operatorStack.push(ch);}} else if (operatorStack.isPoint(ch) || operatorStack.isNum(ch)) { //如果是數或者是小數點，則直接入數棧//numStack.push(ch - 48); // "1+3" '1' => 1//1. 當處理多位數時，不能發現是一個數就立即入棧，因為可能是多位數//2. 在處理數，需要向expression的表達式的index 后再看一位,如果是數就進行掃描，如果是符號才入棧//3. 因此我們需要定義一個變量 字符串，用于拼接//處理多位數keepNum += ch;//如果ch已經是expression的最后一位，就直接入棧if (index == expression.length() - 1) {numStack.push(Double.parseDouble(keepNum));} else {//判斷下一個字符是不是數字，如果是數字，就繼續掃描，如果是運算符，則入棧//注意是看后一位，不是index++if (operatorStack.isOper(expression.substring(index + 1, index + 2).charAt(0))|| operatorStack.isRightBrackets(expression.substring(index + 1, index + 2).charAt(0))) {//如果后一位是運算符，則入棧 keepNum = "1" 或者 "123"numStack.push(Double.parseDouble(keepNum));//最后keepNum必須清空keepNum = "";}}} else if (!operatorStack.isEmpty() && (operatorStack.peek() == 's' ||operatorStack.peek() == '!' ||operatorStack.peek() == 'v' ||operatorStack.peek() == '#' ||operatorStack.peek() == '%')) { //如果棧頂為三角函數算式、開根或者是階乘oper = (int) operatorStack.pop();num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);//把運算的結果入數棧numStack.push(res);}//讓index + 1, 并判斷是否掃描到expression最后.index++;if (index >= expression.length()) {break;}}//當表達式掃描完畢，就順序的從 數棧和符號棧中pop出相應的數和符號，并運行.while (true) {//如果符號棧為空，則計算到最后的結果, 數棧中只有一個數字【結果】if (operatorStack.isEmpty()) {break;}if (operatorStack.peek() == 's' ||operatorStack.peek() == '!' ||operatorStack.peek() == 'v' ||operatorStack.peek() == '#' ||operatorStack.peek() == '%') { //如果棧頂為三角函數算式oper = (int) operatorStack.pop();num1 = numStack.pop();res = numStack.mixedOperation(num1, oper);numStack.push(res);//入棧} else {num1 = numStack.pop();num2 = numStack.pop();oper = (int) operatorStack.pop();res = numStack.cal(num1, num2, oper);numStack.push(res);//入棧}}//將數棧的最后數，pop出，就是結果double res2 = numStack.pop();System.out.println(res2+"ll");return res2;}

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