PR for code review

src/main/java/Input.java

@@ -0,0 +1,20 @@
+import java.util.Scanner;
+
+public class Input {
+
+    public static String[] splitInput(){
+        System.out.println("계산식 입력 : ");
+        Scanner sc = new Scanner(System.in);
+        String input = sc.nextLine();
+
+        String[] splitString = input.split(" ");
+
+        checkInput(splitString);
+
+        return splitString;
+    }
+
+    public static void checkInput(String[] splitInput){
+        if(splitInput.length % 2 == 0) throw new IllegalArgumentException("잘못된 연산입력입니다.");
+    }
+}

src/main/java/Main.java

@@ -0,0 +1,9 @@
+public class Main {
+    public static void main(String[] args){
+        calculate();
+    }
+    public static void calculate(){
+        StringCalculator stringCalculator = new StringCalculator();
+        Output.printOutput(stringCalculator.calculateStr(Input.splitInput()));
+    }
+}

src/main/java/Output.java

@@ -0,0 +1,5 @@
+public class Output {
+    public static void printOutput(int num){
+        System.out.println(num);
+    }
+}

src/main/java/StringCalculator.java

@@ -0,0 +1,47 @@
+import java.util.*;
+
+public class StringCalculator {
+
+    public int calculateStr(String[] inputSplit){
+        int number = Integer.parseInt(inputSplit[0]);
+        for(int i = 0; i < inputSplit.length - 2; i += 2){
+            number = calculate(number, inputSplit[i+1].charAt(0), Integer.parseInt(inputSplit[i+2]));
+        }
+        return number;
+    }
+
+    public int calculate(int firstFactor, char operator, int secondFactor) {
+        if (operator == '+')
+            return add(firstFactor,secondFactor);
+        if (operator == '-')
+            return subtract(firstFactor,secondFactor);
+        if (operator == '*')
+            return multiply(firstFactor,secondFactor);
+        if (operator == '/')
+            return divide(firstFactor,secondFactor);
+
+        throw new RuntimeException("올바르지 않은 연산자");
+    }
+
+
+    public int add(int num1, int num2){
+        return num1 + num2;
+    }
+    public int subtract(int num1, int num2){
+        return num1 - num2;
+    }
+    public int multiply(int num1, int num2){
+        return num1 * num2;
+    }
+    public int divide(int num1, int num2){
+        try {
+            return num1 / num2;
+        } catch(ArithmeticException e){
+            System.out.println("0 으로 나눌수 없음 : " + num1 + "/" + num2);
+        }
+        throw new RuntimeException();
+    }
+
+
+
+}