Refactoring Code To Use OOP

Java Classes & Interfaces/New Calc Engine/src/MathEquation.java

@@ -0,0 +1,68 @@
+public class MathEquation {
+    private double leftVal;
+    private double rightVal;
+    private char opCode;
+    private double result;
+
+    void execute() {
+        switch (this.opCode) {
+            case 'a':
+                this.result = this.leftVal + this.rightVal;
+                break;
+            case 's':
+                this.result = this.leftVal - this.rightVal;
+                break;
+            case 'm':
+                this.result = this.leftVal * this.rightVal;
+                break;
+            case 'd':
+                this.result = this.rightVal != 0 ? this.leftVal / this.rightVal : 0.0d;
+                break;
+            default:
+                System.out.println("Invalid opCode: " + this.opCode);
+                this.result = 0.0d;
+                break;
+        }
+    }
+
+    public MathEquation(double leftVal, double rightVal, char opCode, double result) {
+        this.leftVal = leftVal;
+        this.rightVal = rightVal;
+        this.opCode = opCode;
+        this.result = result;
+    }
+
+    // Setters
+
+    public double getLeftVal() {
+        return leftVal;
+    }
+
+    public void setLeftVal(double leftVal) { 
+        this.leftVal = leftVal; 
+    }
+
+    public double getRightVal() {
+        return rightVal;
+    }
+
+    public void setRightVal(double rightVal) {
+        this.rightVal = rightVal;
+    }
+
+    public char getOpCode() {
+        return opCode;
+    }
+
+    public void setOpCode(char opCode) {
+        this.opCode = opCode;
+    }
+
+    public double getResult() {
+        return result;
+    }
+
+    public void setResult(double result) {
+        this.result = result;
+    }
+}

Java Classes & Interfaces/New Calc Engine/src/NewCalcEngine.java

@@ -1,3 +1,5 @@
+import java.util.ArrayList;
+
 public class NewCalcEngine {
 
     public static void main(String[] args) {
@@ -5,39 +7,26 @@ public class NewCalcEngine {
     }
 
     static void performCalculations() {
-        double[] leftVals = {100.0d, 25.0d, 225.0d, 11.0d};
-        double[] rightVals = {50.0d, 92.0d, 17.0d, 3.0d};
-        char[] opCodes = {'d', 'a', 's', 'm'};
-        double[] results = new double[opCodes.length];
 
-        for (int i = 0; i < opCodes.length; i++) {
-            results[i] = execute(opCodes[i], leftVals[i], rightVals[i]);
-        }
-        for (double currentResult : results)
-            System.out.println("result = " + currentResult);
+        MathEquation[] mathEquation = new MathEquation[4];
+        mathEquation[0] = create(100.0d, 50.0d, 'd');
+        mathEquation[1] = create(25.0d, 92.0d, 'a');
+        mathEquation[2] = create(225.0d, 17.0d, 's');
+        mathEquation[3] = create(11.0d, 3.0d, 'm');
 
+        for (MathEquation equation: mathEquation) {
+            equation.execute();
+            System.out.println("Result = " + equation.result);
+        }
     }
 
-    static double execute(char opCode, double leftVal, double rightVal) {
-        double result;
-        switch (opCode) {
-            case 'a':
-                result = leftVal + rightVal;
-                break;
-            case 's':
-                result = leftVal - rightVal;
-                break;
-            case 'm':
-                result = leftVal * rightVal;
-                break;
-            case 'd':
-                result = rightVal != 0 ? leftVal / rightVal : 0.0d;
-                break;
-            default:
-                System.out.println("Invalid opCode: " + opCode);
-                result = 0.0d;
-                break;
-        }
-        return result;
+    static MathEquation create(double leftVal, double rightVal, char opCode) {
+        MathEquation mathEquation = new MathEquation();
+        
+        mathEquation.leftVal = leftVal;
+        mathEquation.rightVal = rightVal;
+        mathEquation.opCode = opCode;
+
+        return mathEquation;
     }
 }