From 3d4ec74751d394ce69ace03b8d40cd01b57ea3c8 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Tue, 23 Feb 2021 13:59:58 +0900
Subject: [PATCH 01/14] docs(guide): list of implementation functions and TDD
 case

---
 src/README.md | 58 +++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 58 insertions(+)
 create mode 100644 src/README.md

diff --git a/src/README.md b/src/README.md
new file mode 100644
index 0000000..276b0a4
--- /dev/null
+++ b/src/README.md
@@ -0,0 +1,58 @@
+# Java-Calculator
+
+Create a string calculator and write test code for it
+
+## Contributor
+- oereo
+
+## Branch structure
+
+### oereo branch
+* from `oereo/java-calculator[oereo branch]` to `biforest/java-calculator [oereo branch]`
+
+### java-calculator-structure branch
+* Feature branch : Branch to develop the function ex)feature/java-calculator
+* Fix branch : Branch to fix the function ex)fix/java-calculator
+
+## TDD
+### Failure case
+#### (1) When divided by 0
+```console
+ 연산을 입력해주세요 : 2/0  // error
+```
+#### (2) When two or more operation symbols appear in a row
+```console
+ 연산을 입력해주세요 : 2++0  // error
+```
+#### (3) When the operation symbol appears at the beginning
+```console
+ 연산을 입력해주세요 : +2+0  // error
+```
+#### (4) When special characters other than operation symbols are entered
+```console
+ 연산을 입력해주세요 : 2^4  // error
+```
+#### (5) When characters excluding numbers and operators are entered
+```console
+ 연산을 입력해주세요 : 2ㄱㄴ4*4  // error
+```
+
+## Structure
+#### 1. Class
+- Calculator class
+  - `+ class`
+  - `- class`
+  - `* class`
+  - `/ class`
+- Input class
+- Output class
+  - `Error message` output
+  - `Calculation result` output
+- Error exception class
+  - Precautions : only use `try ~ catch`
+- Init class
+  - When an error occurs, reset after outputting an error message
+  - Reset and input when pressing any key value
+    
+#### 2. Algorithm
+- DFS
\ No newline at end of file

From 59160fa38804aec3bcca7ac9b7db0631d9dc1951 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Wed, 24 Feb 2021 14:34:17 +0900
Subject: [PATCH 02/14] docs(guide): add TDD case

---
 src/README.md | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/src/README.md b/src/README.md
index 276b0a4..0680f67 100644
--- a/src/README.md
+++ b/src/README.md
@@ -36,7 +36,10 @@ Create a string calculator and write test code for it
 ```console
  연산을 입력해주세요 : 2ㄱㄴ4*4  // error
 ```
-
+#### (6) When the formula ends with an operation symbol
+```console
+ 연산을 입력해주세요 : 2-1*  // error
+```
 ## Structure
 #### 1. Class
 - Calculator class
@@ -55,4 +58,4 @@ Create a string calculator and write test code for it
   - Reset and input when pressing any key value
     
 #### 2. Algorithm
-- DFS
\ No newline at end of file
+- DFS, Node
\ No newline at end of file

From fd2266adccb23acadc49547a3b67c760d058ee68 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 20:40:48 +0900
Subject: [PATCH 03/14] feat: java-calculator basic structure design and
 implementation

---
 settings.gradle                               |  2 +
 src/main/java/calculator/AddOperation.java    | 19 ++++++
 src/main/java/calculator/Application.java     |  9 +++
 .../calculator/ArithmeticExpressionStack.java | 46 ++++++++++++++
 src/main/java/calculator/Calculator.java      | 60 +++++++++++++++++++
 src/main/java/calculator/DivideOperation.java | 25 ++++++++
 src/main/java/calculator/ErrorException.java  | 17 ++++++
 src/main/java/calculator/InputUserData.java   |  9 +++
 .../java/calculator/MultiplyOperation.java    | 19 ++++++
 src/main/java/calculator/Operation.java       | 14 +++++
 src/main/java/calculator/OutputUserData.java  |  4 ++
 src/main/java/calculator/SubOperation.java    | 19 ++++++
 src/main/java/empty.txt                       |  0
 13 files changed, 243 insertions(+)
 create mode 100644 settings.gradle
 create mode 100644 src/main/java/calculator/AddOperation.java
 create mode 100644 src/main/java/calculator/Application.java
 create mode 100644 src/main/java/calculator/ArithmeticExpressionStack.java
 create mode 100644 src/main/java/calculator/Calculator.java
 create mode 100644 src/main/java/calculator/DivideOperation.java
 create mode 100644 src/main/java/calculator/ErrorException.java
 create mode 100644 src/main/java/calculator/InputUserData.java
 create mode 100644 src/main/java/calculator/MultiplyOperation.java
 create mode 100644 src/main/java/calculator/Operation.java
 create mode 100644 src/main/java/calculator/OutputUserData.java
 create mode 100644 src/main/java/calculator/SubOperation.java
 delete mode 100644 src/main/java/empty.txt

diff --git a/settings.gradle b/settings.gradle
new file mode 100644
index 0000000..bcf30bf
--- /dev/null
+++ b/settings.gradle
@@ -0,0 +1,2 @@
+rootProject.name = 'java-calculator'
+
diff --git a/src/main/java/calculator/AddOperation.java b/src/main/java/calculator/AddOperation.java
new file mode 100644
index 0000000..1b0f64c
--- /dev/null
+++ b/src/main/java/calculator/AddOperation.java
@@ -0,0 +1,19 @@
+package calculator;
+
+public class AddOperation implements OperationInterface {
+    @Override
+    public int operationPriority() {
+        return 1;
+    }
+
+    @Override
+    public String operationName() {
+        return "+";
+    }
+
+    @Override
+    public int calculation(int beforeNumber, int afterNumber) {
+        int Result = beforeNumber + afterNumber;
+        return Result;
+    }
+}
diff --git a/src/main/java/calculator/Application.java b/src/main/java/calculator/Application.java
new file mode 100644
index 0000000..2800320
--- /dev/null
+++ b/src/main/java/calculator/Application.java
@@ -0,0 +1,9 @@
+package calculator;
+
+
+public class Application {
+    public static void main(String[] args) {
+        Calculator calculator = new Calculator();
+        calculator.calculation();
+    }
+}
diff --git a/src/main/java/calculator/ArithmeticExpressionStack.java b/src/main/java/calculator/ArithmeticExpressionStack.java
new file mode 100644
index 0000000..2606b1a
--- /dev/null
+++ b/src/main/java/calculator/ArithmeticExpressionStack.java
@@ -0,0 +1,46 @@
+package calculator;
+
+
+interface Stack{
+    boolean isEmpty();
+    String pop();
+    void clear();
+}
+
+public class ArithmeticExpressionStack implements Stack {
+    private int stackSize;
+    private int flag;
+    private String stack[];
+
+    public ArithmeticExpressionStack(String[] equation, int stackSize){
+        clear();
+        flag = 0;
+        this.stackSize = stackSize;
+        stack = equation;
+    }
+
+    public String pop(){
+        if(isEmpty()){
+            return "없는데?";
+        }
+        else{
+            return stack[flag++];
+        }
+    }
+
+    public boolean isEmpty(){
+        return (flag == this.stackSize);
+    }
+
+    public void clear(){
+        if(!isEmpty()){
+            flag = -1;
+            this.stackSize = stackSize;
+        }
+    }
+
+    public int getStackSize(){
+        return this.stackSize;
+    }
+
+}
diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
new file mode 100644
index 0000000..9b26899
--- /dev/null
+++ b/src/main/java/calculator/Calculator.java
@@ -0,0 +1,60 @@
+package calculator;
+
+import java.util.Scanner;
+
+
+public class Calculator {
+    public void calculation(){
+        String[] equation_list = getEquation();
+        ArithmeticExpressionStack arithmeticExpressionStack = new ArithmeticExpressionStack(equation_list, equation_list.length);
+        OperatorSetting(arithmeticExpressionStack, equation_list.length);
+
+    }
+
+    public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack, int equationLength) {
+        ErrorException exception = new ErrorException();
+        String firstString = arithmeticExpressionStack.pop();
+        int firstNumber = exception.NumericalError(firstString);
+
+        for(int i = 0; i<(arithmeticExpressionStack.getStackSize())/2;i++){
+            String operator = arithmeticExpressionStack.pop();
+            String secondString = arithmeticExpressionStack.pop();
+            int secondNumber = exception.NumericalError(secondString);
+            firstNumber = chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
+        }
+        arithmeticExpressionStack.clear();
+        System.out.println("결과");
+        System.out.println(firstNumber);
+    }
+
+    private int chooseOperatorAndCalculate(int firstNumber, String operator, int SecondNumber){
+        AddOperation addOperation = new AddOperation();
+        SubOperation subOperation = new SubOperation();
+        MultiplyOperation multiplyOperation = new MultiplyOperation();
+        DivideOperation divideOperation = new DivideOperation();
+        int result = 0;
+        if (operator.equals(addOperation.operationName())){
+            result = addOperation.calculation(firstNumber, SecondNumber);
+        }
+        if (operator.equals(subOperation.operationName())){
+            result = subOperation.calculation(firstNumber, SecondNumber);
+        }
+        if (operator.equals(multiplyOperation.operationName())){
+            result = multiplyOperation.calculation(firstNumber, SecondNumber);
+        }
+        if (operator.equals(divideOperation.operationName())){
+            result = divideOperation.calculation(firstNumber, SecondNumber);
+        }
+
+        return result;
+    }
+
+
+    public String[] getEquation(){
+        Scanner scanner = new Scanner(System.in);
+        System.out.print("수식을 입력해주세요 : ");
+        String value = scanner.nextLine();
+        String[] values = value.split(" ");
+        return values;
+    }
+}
diff --git a/src/main/java/calculator/DivideOperation.java b/src/main/java/calculator/DivideOperation.java
new file mode 100644
index 0000000..33e8c7b
--- /dev/null
+++ b/src/main/java/calculator/DivideOperation.java
@@ -0,0 +1,25 @@
+package calculator;
+
+public class DivideOperation implements OperationInterface {
+    @Override
+    public int operationPriority() {
+        return 1;
+    }
+
+    @Override
+    public String operationName() {
+        return "/";
+    }
+
+    @Override
+    public int calculation(int beforeNumber, int afterNumber) {
+        try{
+            int Result = beforeNumber / afterNumber;
+            return Result;
+        }
+        catch (ArithmeticException e){
+            System.out.println("0으로 나눌수가 없습니다.");
+        }
+        return 0;
+    }
+}
diff --git a/src/main/java/calculator/ErrorException.java b/src/main/java/calculator/ErrorException.java
new file mode 100644
index 0000000..9289555
--- /dev/null
+++ b/src/main/java/calculator/ErrorException.java
@@ -0,0 +1,17 @@
+package calculator;
+
+import java.util.InputMismatchException;
+
+public class ErrorException {
+    public int NumericalError(String number) {
+        int numberConverted = 0;
+        try {
+            numberConverted = Integer.parseInt(number);
+        } catch (NumberFormatException e) {
+            System.out.println("잘못된 연산기호 입니다.");
+            Calculator calculator = new Calculator();
+            calculator.calculation();
+        }
+        return numberConverted;
+    }
+}
diff --git a/src/main/java/calculator/InputUserData.java b/src/main/java/calculator/InputUserData.java
new file mode 100644
index 0000000..9b97a4b
--- /dev/null
+++ b/src/main/java/calculator/InputUserData.java
@@ -0,0 +1,9 @@
+package calculator;
+import java.util.Scanner;
+
+public class InputUserData {
+    public Scanner getEquation(){
+        Scanner scanner = new Scanner(System.in);
+        return scanner;
+    }
+}
diff --git a/src/main/java/calculator/MultiplyOperation.java b/src/main/java/calculator/MultiplyOperation.java
new file mode 100644
index 0000000..f03451a
--- /dev/null
+++ b/src/main/java/calculator/MultiplyOperation.java
@@ -0,0 +1,19 @@
+package calculator;
+
+public class MultiplyOperation implements OperationInterface {
+    @Override
+    public int operationPriority() {
+        return 1;
+    }
+
+    @Override
+    public String operationName() {
+        return "*";
+    }
+
+    @Override
+    public int calculation(int beforeNumber, int afterNumber) {
+        int Result = beforeNumber * afterNumber;
+        return Result;
+    }
+}
diff --git a/src/main/java/calculator/Operation.java b/src/main/java/calculator/Operation.java
new file mode 100644
index 0000000..d47ad26
--- /dev/null
+++ b/src/main/java/calculator/Operation.java
@@ -0,0 +1,14 @@
+package calculator;
+
+interface OperationInterface {
+    public int operationPriority();
+
+    public String operationName();
+
+    public int calculation(int beforeNumber, int afterNumber);
+}
+
+
+
+
+
diff --git a/src/main/java/calculator/OutputUserData.java b/src/main/java/calculator/OutputUserData.java
new file mode 100644
index 0000000..3e00b2a
--- /dev/null
+++ b/src/main/java/calculator/OutputUserData.java
@@ -0,0 +1,4 @@
+package calculator;
+
+public class OutputUserData {
+}
diff --git a/src/main/java/calculator/SubOperation.java b/src/main/java/calculator/SubOperation.java
new file mode 100644
index 0000000..a0adeec
--- /dev/null
+++ b/src/main/java/calculator/SubOperation.java
@@ -0,0 +1,19 @@
+package calculator;
+
+public class SubOperation implements OperationInterface {
+    @Override
+    public int operationPriority() {
+        return 1;
+    }
+
+    @Override
+    public String operationName() {
+        return "-";
+    }
+
+    @Override
+    public int calculation(int beforeNumber, int afterNumber) {
+        int Result = beforeNumber - afterNumber;
+        return Result;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/empty.txt b/src/main/java/empty.txt
deleted file mode 100644
index e69de29..0000000

From 25e3e7a64f45a903386e724d22bd74d449a59f33 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 20:49:26 +0900
Subject: [PATCH 04/14] feat: add a method to initialize and rerun the
 calculator

---
 src/main/java/calculator/Calculator.java     | 13 +++++++++++++
 src/main/java/calculator/ErrorException.java |  2 +-
 2 files changed, 14 insertions(+), 1 deletion(-)

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index 9b26899..5e36eba 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -25,6 +25,7 @@ public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack,
         arithmeticExpressionStack.clear();
         System.out.println("결과");
         System.out.println(firstNumber);
+        init();
     }
 
     private int chooseOperatorAndCalculate(int firstNumber, String operator, int SecondNumber){
@@ -49,6 +50,18 @@ private int chooseOperatorAndCalculate(int firstNumber, String operator, int Sec
         return result;
     }
 
+    public void init(){
+        Scanner scanner = new Scanner(System.in);
+        System.out.println("계산을 계속 진행하시려면 1, 멈추시려면 2를 눌러주세요");
+        String value = scanner.nextLine();
+
+        if(value.equals("1")){
+            calculation();
+        }
+        else{
+            System.exit(0);
+        }
+    }
 
     public String[] getEquation(){
         Scanner scanner = new Scanner(System.in);
diff --git a/src/main/java/calculator/ErrorException.java b/src/main/java/calculator/ErrorException.java
index 9289555..d61065c 100644
--- a/src/main/java/calculator/ErrorException.java
+++ b/src/main/java/calculator/ErrorException.java
@@ -10,7 +10,7 @@ public int NumericalError(String number) {
         } catch (NumberFormatException e) {
             System.out.println("잘못된 연산기호 입니다.");
             Calculator calculator = new Calculator();
-            calculator.calculation();
+            calculator.init();
         }
         return numberConverted;
     }

From 3f697e6fd8c10f7072f994e1e613091922d91c7d Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 22:06:43 +0900
Subject: [PATCH 05/14] feat: add exception message list

---
 src/main/java/calculator/Calculator.java     |  7 +++++--
 src/main/java/calculator/ErrorException.java |  4 ++++
 src/main/java/calculator/Message.java        | 19 +++++++++++++++++++
 src/main/java/calculator/OutputUserData.java |  4 ----
 4 files changed, 28 insertions(+), 6 deletions(-)
 create mode 100644 src/main/java/calculator/Message.java
 delete mode 100644 src/main/java/calculator/OutputUserData.java

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index 5e36eba..4c72217 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -4,6 +4,7 @@
 
 
 public class Calculator {
+    Message message = new Message();
     public void calculation(){
         String[] equation_list = getEquation();
         ArithmeticExpressionStack arithmeticExpressionStack = new ArithmeticExpressionStack(equation_list, equation_list.length);
@@ -22,8 +23,7 @@ public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack,
             int secondNumber = exception.NumericalError(secondString);
             firstNumber = chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
         }
-        arithmeticExpressionStack.clear();
-        System.out.println("결과");
+        System.out.print("결과 : ");
         System.out.println(firstNumber);
         init();
     }
@@ -46,6 +46,9 @@ private int chooseOperatorAndCalculate(int firstNumber, String operator, int Sec
         if (operator.equals(divideOperation.operationName())){
             result = divideOperation.calculation(firstNumber, SecondNumber);
         }
+        else{
+            message.exceptionResult("NOT_OPERATOR");
+        }
 
         return result;
     }
diff --git a/src/main/java/calculator/ErrorException.java b/src/main/java/calculator/ErrorException.java
index d61065c..7c0e4bb 100644
--- a/src/main/java/calculator/ErrorException.java
+++ b/src/main/java/calculator/ErrorException.java
@@ -14,4 +14,8 @@ public int NumericalError(String number) {
         }
         return numberConverted;
     }
+
+    public void OperatorError(){
+
+    }
 }
diff --git a/src/main/java/calculator/Message.java b/src/main/java/calculator/Message.java
new file mode 100644
index 0000000..7141417
--- /dev/null
+++ b/src/main/java/calculator/Message.java
@@ -0,0 +1,19 @@
+package calculator;
+
+import java.lang.reflect.Field;
+import java.util.HashMap;
+
+public class Message {
+    HashMap<String, String> exceptionMessageList = new HashMap<String, String>();
+    public void calculationResult(){
+        System.out.println("");
+    }
+    private void exceptionMessageList(){
+        exceptionMessageList.put("NOT_OPERATOR", "사칙연산 기호에 해당하지 않는 기호가 존재합니다.");
+    }
+
+    public void exceptionResult(String exceptionKeyword){
+        exceptionMessageList();
+        System.out.println(exceptionMessageList.get(exceptionKeyword));
+    }
+}
diff --git a/src/main/java/calculator/OutputUserData.java b/src/main/java/calculator/OutputUserData.java
deleted file mode 100644
index 3e00b2a..0000000
--- a/src/main/java/calculator/OutputUserData.java
+++ /dev/null
@@ -1,4 +0,0 @@
-package calculator;
-
-public class OutputUserData {
-}

From a0723ccf5aa51739347d18c0e54f0b76f780ac07 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 22:19:28 +0900
Subject: [PATCH 06/14] refactor: fix message format in ErrorException and
 Message class

---
 src/main/java/calculator/Calculator.java     | 14 ++++++++------
 src/main/java/calculator/ErrorException.java |  7 ++-----
 src/main/java/calculator/Message.java        |  6 ++++--
 3 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index 4c72217..f2be843 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -23,8 +23,10 @@ public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack,
             int secondNumber = exception.NumericalError(secondString);
             firstNumber = chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
         }
-        System.out.print("결과 : ");
-        System.out.println(firstNumber);
+
+        if(firstNumber != 0){
+            message.calculationResult(firstNumber);
+        }
         init();
     }
 
@@ -37,13 +39,13 @@ private int chooseOperatorAndCalculate(int firstNumber, String operator, int Sec
         if (operator.equals(addOperation.operationName())){
             result = addOperation.calculation(firstNumber, SecondNumber);
         }
-        if (operator.equals(subOperation.operationName())){
+        else if (operator.equals(subOperation.operationName())){
             result = subOperation.calculation(firstNumber, SecondNumber);
         }
-        if (operator.equals(multiplyOperation.operationName())){
+        else if (operator.equals(multiplyOperation.operationName())){
             result = multiplyOperation.calculation(firstNumber, SecondNumber);
         }
-        if (operator.equals(divideOperation.operationName())){
+        else if (operator.equals(divideOperation.operationName())){
             result = divideOperation.calculation(firstNumber, SecondNumber);
         }
         else{
@@ -55,7 +57,7 @@ private int chooseOperatorAndCalculate(int firstNumber, String operator, int Sec
 
     public void init(){
         Scanner scanner = new Scanner(System.in);
-        System.out.println("계산을 계속 진행하시려면 1, 멈추시려면 2를 눌러주세요");
+        System.out.println("계산을 계속 진행하시려면 1, 멈추시려면 임의의 다른키를 눌러주세요");
         String value = scanner.nextLine();
 
         if(value.equals("1")){
diff --git a/src/main/java/calculator/ErrorException.java b/src/main/java/calculator/ErrorException.java
index 7c0e4bb..ca64869 100644
--- a/src/main/java/calculator/ErrorException.java
+++ b/src/main/java/calculator/ErrorException.java
@@ -3,19 +3,16 @@
 import java.util.InputMismatchException;
 
 public class ErrorException {
+    Message message = new Message();
     public int NumericalError(String number) {
         int numberConverted = 0;
         try {
             numberConverted = Integer.parseInt(number);
         } catch (NumberFormatException e) {
-            System.out.println("잘못된 연산기호 입니다.");
+            message.exceptionResult("INVALID_EQUATION");
             Calculator calculator = new Calculator();
             calculator.init();
         }
         return numberConverted;
     }
-
-    public void OperatorError(){
-
-    }
 }
diff --git a/src/main/java/calculator/Message.java b/src/main/java/calculator/Message.java
index 7141417..b497d61 100644
--- a/src/main/java/calculator/Message.java
+++ b/src/main/java/calculator/Message.java
@@ -5,11 +5,13 @@
 
 public class Message {
     HashMap<String, String> exceptionMessageList = new HashMap<String, String>();
-    public void calculationResult(){
-        System.out.println("");
+    public void calculationResult(int result){
+        System.out.print("결과 : ");
+        System.out.println(result);
     }
     private void exceptionMessageList(){
         exceptionMessageList.put("NOT_OPERATOR", "사칙연산 기호에 해당하지 않는 기호가 존재합니다.");
+        exceptionMessageList.put("INVALID_EQUATION", "잘못된 연산식입니다.");
     }
 
     public void exceptionResult(String exceptionKeyword){

From 9aab01072aacd4785f1eddc5c393d796384be0b0 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 22:22:19 +0900
Subject: [PATCH 07/14] refactor: delete unused parameter in OperatorSetting
 class

---
 src/main/java/calculator/Calculator.java | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index f2be843..e446ea1 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -8,11 +8,11 @@ public class Calculator {
     public void calculation(){
         String[] equation_list = getEquation();
         ArithmeticExpressionStack arithmeticExpressionStack = new ArithmeticExpressionStack(equation_list, equation_list.length);
-        OperatorSetting(arithmeticExpressionStack, equation_list.length);
+        OperatorSetting(arithmeticExpressionStack);
 
     }
 
-    public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack, int equationLength) {
+    public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack) {
         ErrorException exception = new ErrorException();
         String firstString = arithmeticExpressionStack.pop();
         int firstNumber = exception.NumericalError(firstString);

From ef52572c6529f210f25a77ee8ac54ff50b2dc87b Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 22:33:54 +0900
Subject: [PATCH 08/14] refactor: delete the userInputData class

---
 src/main/java/calculator/InputUserData.java | 9 ---------
 1 file changed, 9 deletions(-)
 delete mode 100644 src/main/java/calculator/InputUserData.java

diff --git a/src/main/java/calculator/InputUserData.java b/src/main/java/calculator/InputUserData.java
deleted file mode 100644
index 9b97a4b..0000000
--- a/src/main/java/calculator/InputUserData.java
+++ /dev/null
@@ -1,9 +0,0 @@
-package calculator;
-import java.util.Scanner;
-
-public class InputUserData {
-    public Scanner getEquation(){
-        Scanner scanner = new Scanner(System.in);
-        return scanner;
-    }
-}

From 9199b85caa1292f85e600ff6a3624297ca047b3d Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 22:38:46 +0900
Subject: [PATCH 09/14] refactor: reset variable names that don't fit naming

---
 src/main/java/calculator/Calculator.java | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index e446ea1..fbf01d2 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -15,17 +15,17 @@ public void calculation(){
     public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack) {
         ErrorException exception = new ErrorException();
         String firstString = arithmeticExpressionStack.pop();
-        int firstNumber = exception.NumericalError(firstString);
+        int cumulativeResult = exception.NumericalError(firstString);
 
         for(int i = 0; i<(arithmeticExpressionStack.getStackSize())/2;i++){
             String operator = arithmeticExpressionStack.pop();
             String secondString = arithmeticExpressionStack.pop();
             int secondNumber = exception.NumericalError(secondString);
-            firstNumber = chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
+            cumulativeResult = chooseOperatorAndCalculate(cumulativeResult, operator, secondNumber);
         }
 
-        if(firstNumber != 0){
-            message.calculationResult(firstNumber);
+        if(cumulativeResult != 0){
+            message.calculationResult(cumulativeResult);
         }
         init();
     }

From 860bcd76b4129866c9c40b8264035c4268b9096e Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 22:40:37 +0900
Subject: [PATCH 10/14] refactor: rename variable name [exception]

---
 src/main/java/calculator/Calculator.java | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index fbf01d2..8867f39 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -13,14 +13,14 @@ public void calculation(){
     }
 
     public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack) {
-        ErrorException exception = new ErrorException();
+        ErrorException exceptionCheck = new ErrorException();
         String firstString = arithmeticExpressionStack.pop();
-        int cumulativeResult = exception.NumericalError(firstString);
+        int cumulativeResult = exceptionCheck.NumericalError(firstString);
 
         for(int i = 0; i<(arithmeticExpressionStack.getStackSize())/2;i++){
             String operator = arithmeticExpressionStack.pop();
             String secondString = arithmeticExpressionStack.pop();
-            int secondNumber = exception.NumericalError(secondString);
+            int secondNumber = exceptionCheck.NumericalError(secondString);
             cumulativeResult = chooseOperatorAndCalculate(cumulativeResult, operator, secondNumber);
         }
 

From 529f7e494ed3664f3e992579c71d4de194c8aa68 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Thu, 25 Feb 2021 23:45:45 +0900
Subject: [PATCH 11/14] feat: add TDD basic format and test case for calculator
 class

---
 src/main/java/calculator/Calculator.java     |  2 +-
 src/test/java/calculator/CalculatorTest.java | 69 ++++++++++++++++++++
 2 files changed, 70 insertions(+), 1 deletion(-)
 create mode 100644 src/test/java/calculator/CalculatorTest.java

diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index 8867f39..a6702ba 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -30,7 +30,7 @@ public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack)
         init();
     }
 
-    private int chooseOperatorAndCalculate(int firstNumber, String operator, int SecondNumber){
+    public int chooseOperatorAndCalculate(int firstNumber, String operator, int SecondNumber){
         AddOperation addOperation = new AddOperation();
         SubOperation subOperation = new SubOperation();
         MultiplyOperation multiplyOperation = new MultiplyOperation();
diff --git a/src/test/java/calculator/CalculatorTest.java b/src/test/java/calculator/CalculatorTest.java
new file mode 100644
index 0000000..a50aec1
--- /dev/null
+++ b/src/test/java/calculator/CalculatorTest.java
@@ -0,0 +1,69 @@
+package calculator;
+
+import org.junit.jupiter.api.BeforeEach;
+import org.junit.jupiter.api.Test;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+class CalculatorTest {
+
+    @BeforeEach
+    void setUp() {
+        Calculator calculator = new Calculator();
+    }
+
+    @Test
+    void calculation() {
+//        Calculator calculator = new Calculator();
+//        calculator.calculation();
+    }
+
+    @Test
+    void operatorSetting() {
+    }
+
+    @Test
+    void addChooseOperatorAndCalculate(){
+        Calculator calculator = new Calculator();
+        int firstNumber = 2;
+        String operator = "+";
+        int secondNumber = 3;
+        int result = 0;
+        result = calculator.chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
+        assertEquals(5, result);
+    }
+
+    @Test
+    void subChooseOperatorAndCalculate(){
+        Calculator calculator = new Calculator();
+        int firstNumber = 2;
+        String operator = "-";
+        int secondNumber = 3;
+        int result = 0;
+        result = calculator.chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
+        assertEquals(-1, result);
+    }
+
+    @Test
+    void multiplyChooseOperatorAndCalculate(){
+        Calculator calculator = new Calculator();
+        int firstNumber = 2;
+        String operator = "*";
+        int secondNumber = 3;
+        int result = 0;
+        result = calculator.chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
+        assertEquals(6, result);
+    }
+
+    @Test
+    void divideChooseOperatorAndCalculate(){
+        Calculator calculator = new Calculator();
+        int firstNumber = 9;
+        String operator = "/";
+        int secondNumber = 3;
+        int result = 0;
+        result = calculator.chooseOperatorAndCalculate(firstNumber, operator, secondNumber);
+        assertEquals(3, result);
+    }
+
+}
\ No newline at end of file

From 02edb1f38313acb1f0f9f343ef07966c4bc4e290 Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Fri, 26 Feb 2021 00:46:49 +0900
Subject: [PATCH 12/14] refactor: fix exception handling part divided by 0

---
 src/main/java/calculator/DivideOperation.java | 3 ++-
 src/main/java/calculator/Message.java         | 1 +
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/src/main/java/calculator/DivideOperation.java b/src/main/java/calculator/DivideOperation.java
index 33e8c7b..1efd04d 100644
--- a/src/main/java/calculator/DivideOperation.java
+++ b/src/main/java/calculator/DivideOperation.java
@@ -13,12 +13,13 @@ public String operationName() {
 
     @Override
     public int calculation(int beforeNumber, int afterNumber) {
+        Message message = new Message();
         try{
             int Result = beforeNumber / afterNumber;
             return Result;
         }
         catch (ArithmeticException e){
-            System.out.println("0으로 나눌수가 없습니다.");
+            message.exceptionResult("INVALID_DIVIDE");
         }
         return 0;
     }
diff --git a/src/main/java/calculator/Message.java b/src/main/java/calculator/Message.java
index b497d61..463313a 100644
--- a/src/main/java/calculator/Message.java
+++ b/src/main/java/calculator/Message.java
@@ -12,6 +12,7 @@ public void calculationResult(int result){
     private void exceptionMessageList(){
         exceptionMessageList.put("NOT_OPERATOR", "사칙연산 기호에 해당하지 않는 기호가 존재합니다.");
         exceptionMessageList.put("INVALID_EQUATION", "잘못된 연산식입니다.");
+        exceptionMessageList.put("INVALID_DIVIDE", "0으로 나눌수가 없습니다.");
     }
 
     public void exceptionResult(String exceptionKeyword){

From c3b416cf8796131f0c107adc7a25a23c29adfe4f Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Fri, 26 Feb 2021 02:06:54 +0900
Subject: [PATCH 13/14] feat: add comments to those classes and methods

---
 src/main/java/calculator/Application.java     |  2 +
 .../calculator/ArithmeticExpressionStack.java |  2 +-
 src/main/java/calculator/Calculator.java      | 54 +++++++++++++++++++
 src/main/java/calculator/ErrorException.java  |  7 +++
 src/main/java/calculator/Message.java         | 12 ++++-
 5 files changed, 75 insertions(+), 2 deletions(-)

diff --git a/src/main/java/calculator/Application.java b/src/main/java/calculator/Application.java
index 2800320..62e6657 100644
--- a/src/main/java/calculator/Application.java
+++ b/src/main/java/calculator/Application.java
@@ -3,6 +3,8 @@
 
 public class Application {
     public static void main(String[] args) {
+
+        // Declare calculator object and start calculation
         Calculator calculator = new Calculator();
         calculator.calculation();
     }
diff --git a/src/main/java/calculator/ArithmeticExpressionStack.java b/src/main/java/calculator/ArithmeticExpressionStack.java
index 2606b1a..1762174 100644
--- a/src/main/java/calculator/ArithmeticExpressionStack.java
+++ b/src/main/java/calculator/ArithmeticExpressionStack.java
@@ -21,7 +21,7 @@ public ArithmeticExpressionStack(String[] equation, int stackSize){
 
     public String pop(){
         if(isEmpty()){
-            return "없는데?";
+            return "스택이 존재하지 않습니다.";
         }
         else{
             return stack[flag++];
diff --git a/src/main/java/calculator/Calculator.java b/src/main/java/calculator/Calculator.java
index a6702ba..10e701e 100644
--- a/src/main/java/calculator/Calculator.java
+++ b/src/main/java/calculator/Calculator.java
@@ -5,6 +5,15 @@
 
 public class Calculator {
     Message message = new Message();
+
+    /**
+     * calculation method
+     * 1. getEquation - Receives numeric expression in string format entered by user
+     * 2. Put numeric expressions on the stack
+     * 3. Passing the stack to the operatorSetting method
+     *
+     * return type : void
+     */
     public void calculation(){
         String[] equation_list = getEquation();
         ArithmeticExpressionStack arithmeticExpressionStack = new ArithmeticExpressionStack(equation_list, equation_list.length);
@@ -12,42 +21,74 @@ public void calculation(){
 
     }
 
+    /**
+     * OperatorSetting method
+     * 1. Pop each operator and number onto the stack.
+     * 2. Perform error exception check and calculate
+     * 3. After the calculation process is complete, call init() to determine whether to return the calculator
+     *
+     * return type : void
+     */
     public void OperatorSetting(ArithmeticExpressionStack arithmeticExpressionStack) {
         ErrorException exceptionCheck = new ErrorException();
         String firstString = arithmeticExpressionStack.pop();
+
+        // Error checking when converting string to int
         int cumulativeResult = exceptionCheck.NumericalError(firstString);
 
         for(int i = 0; i<(arithmeticExpressionStack.getStackSize())/2;i++){
             String operator = arithmeticExpressionStack.pop();
             String secondString = arithmeticExpressionStack.pop();
             int secondNumber = exceptionCheck.NumericalError(secondString);
+
+            // calculated value are continuously accumulated
             cumulativeResult = chooseOperatorAndCalculate(cumulativeResult, operator, secondNumber);
         }
 
         if(cumulativeResult != 0){
             message.calculationResult(cumulativeResult);
         }
+
+        // Whether to re-execute after calculation
         init();
     }
 
+    /**
+     * chooseOperatorAndCalculate method
+     * 1. Pop each operator and number onto the stack.
+     * 2. Perform error exception check and calculate
+     * 3. After the calculation process is complete, call init() to determine whether to return the calculator
+     *
+     * return type : int
+     */
     public int chooseOperatorAndCalculate(int firstNumber, String operator, int SecondNumber){
         AddOperation addOperation = new AddOperation();
         SubOperation subOperation = new SubOperation();
         MultiplyOperation multiplyOperation = new MultiplyOperation();
         DivideOperation divideOperation = new DivideOperation();
         int result = 0;
+
+        // When the operator is equal to "+"
         if (operator.equals(addOperation.operationName())){
             result = addOperation.calculation(firstNumber, SecondNumber);
         }
+
+        // When the operator is equal to "-"
         else if (operator.equals(subOperation.operationName())){
             result = subOperation.calculation(firstNumber, SecondNumber);
         }
+
+        // When the operator is equal to "*"
         else if (operator.equals(multiplyOperation.operationName())){
             result = multiplyOperation.calculation(firstNumber, SecondNumber);
         }
+
+        // When the operator is equal to "/"
         else if (operator.equals(divideOperation.operationName())){
             result = divideOperation.calculation(firstNumber, SecondNumber);
         }
+
+        // Raise error when a symbol that does not correspond to the arithmetic operations(+, -, *, /) comes
         else{
             message.exceptionResult("NOT_OPERATOR");
         }
@@ -55,6 +96,13 @@ else if (operator.equals(divideOperation.operationName())){
         return result;
     }
 
+    /**
+     * init method
+     * - Input "1" to redo calculator.
+     * - Input another key to exit
+     *
+     * return type : void
+     */
     public void init(){
         Scanner scanner = new Scanner(System.in);
         System.out.println("계산을 계속 진행하시려면 1, 멈추시려면 임의의 다른키를 눌러주세요");
@@ -68,6 +116,12 @@ public void init(){
         }
     }
 
+    /**
+     * getEquation method
+     * - Method to receive user input data
+     *
+     * return type : void
+     */
     public String[] getEquation(){
         Scanner scanner = new Scanner(System.in);
         System.out.print("수식을 입력해주세요 : ");
diff --git a/src/main/java/calculator/ErrorException.java b/src/main/java/calculator/ErrorException.java
index ca64869..33f64b8 100644
--- a/src/main/java/calculator/ErrorException.java
+++ b/src/main/java/calculator/ErrorException.java
@@ -4,6 +4,13 @@
 
 public class ErrorException {
     Message message = new Message();
+
+    /**
+     * NumericalError method
+     * - Raise error when string is not converted to int
+     *
+     * return type : void
+     */
     public int NumericalError(String number) {
         int numberConverted = 0;
         try {
diff --git a/src/main/java/calculator/Message.java b/src/main/java/calculator/Message.java
index 463313a..fc6db1f 100644
--- a/src/main/java/calculator/Message.java
+++ b/src/main/java/calculator/Message.java
@@ -1,20 +1,30 @@
 package calculator;
 
-import java.lang.reflect.Field;
 import java.util.HashMap;
 
+/**
+ * Message class
+ * - message output class
+ *
+ * return type : void
+ */
 public class Message {
     HashMap<String, String> exceptionMessageList = new HashMap<String, String>();
+
+    // Result output method when operation is normally performed
     public void calculationResult(int result){
         System.out.print("결과 : ");
         System.out.println(result);
     }
+
+    // Error message list management method
     private void exceptionMessageList(){
         exceptionMessageList.put("NOT_OPERATOR", "사칙연산 기호에 해당하지 않는 기호가 존재합니다.");
         exceptionMessageList.put("INVALID_EQUATION", "잘못된 연산식입니다.");
         exceptionMessageList.put("INVALID_DIVIDE", "0으로 나눌수가 없습니다.");
     }
 
+    // Error message output method
     public void exceptionResult(String exceptionKeyword){
         exceptionMessageList();
         System.out.println(exceptionMessageList.get(exceptionKeyword));

From 825f9c8d958d8ab44f1e37a07518d048a4dccdbd Mon Sep 17 00:00:00 2001
From: Sehoon In <dlstpgns0406@gmail.com>
Date: Fri, 26 Feb 2021 10:23:22 +0900
Subject: [PATCH 14/14] feat: add invalid test case

---
 src/test/java/calculator/CalculatorTest.java | 18 ++++++++++++++++--
 1 file changed, 16 insertions(+), 2 deletions(-)

diff --git a/src/test/java/calculator/CalculatorTest.java b/src/test/java/calculator/CalculatorTest.java
index a50aec1..943ea75 100644
--- a/src/test/java/calculator/CalculatorTest.java
+++ b/src/test/java/calculator/CalculatorTest.java
@@ -2,6 +2,7 @@
 
 import org.junit.jupiter.api.BeforeEach;
 import org.junit.jupiter.api.Test;
+import org.junit.jupiter.api.function.Executable;
 
 import static org.junit.jupiter.api.Assertions.*;
 
@@ -14,8 +15,6 @@ void setUp() {
 
     @Test
     void calculation() {
-//        Calculator calculator = new Calculator();
-//        calculator.calculation();
     }
 
     @Test
@@ -66,4 +65,19 @@ void divideChooseOperatorAndCalculate(){
         assertEquals(3, result);
     }
 
+    @Test
+    void invalidCalculation(){
+        // todo refactoring
+        assertThrows(NumberFormatException.class, new Executable() {
+            @Override
+            public void execute() throws Throwable {
+                Calculator calculator = new Calculator();
+
+                String[] equation_list = {"+", "1", "+"};
+                ArithmeticExpressionStack arithmeticExpressionStack = new ArithmeticExpressionStack(equation_list, equation_list.length);
+
+                calculator.OperatorSetting(arithmeticExpressionStack);
+            }
+        });
+    }
 }
\ No newline at end of file