Merge 4f58c4323b12667212a929a7f599ed6ad2698aea into 5706be95854cd14023a646b5a08307e1b69df29c

src/main/java/com/zipcodewilmington/arrayutility/ArrayUtility.java

@@ -1,7 +1,83 @@
 package com.zipcodewilmington.arrayutility;
 
+import java.lang.reflect.Array;
+import java.lang.reflect.ParameterizedType;
+import java.lang.reflect.Type;
+import java.util.ArrayList;
+import java.util.Arrays;
+
 /**
  * Created by leon on 3/6/18.
  */
-public class ArrayUtility {
+public class ArrayUtility<T> {
+
+    private T[] inputArray;
+
+    public ArrayUtility(T[] input) {
+        this.inputArray = input;
+    }
+
+    private T[] concatenate(T[] arrayToMerge) {
+        T[] result = Arrays.copyOf(this.inputArray, this.inputArray.length + arrayToMerge.length);
+        System.arraycopy(arrayToMerge, 0, result, this.inputArray.length, arrayToMerge.length);
+        return result;
+    }
+
+    private Integer getNumberOfOccurrences(T[] array, T valueToEvaluate) {
+        Integer count = 0;
+        for (T item : array) {
+            if (item == valueToEvaluate) {
+                count++;
+            }
+        }
+        return count;
+    }
+
+    public Integer getNumberOfOccurrences(T valueToEvaluate) {
+         return getNumberOfOccurrences(this.inputArray, valueToEvaluate);
+    }
+
+    public Integer countDuplicatesInMerge(T[] arrayToMerge, T valueToEvaluate) {
+        T[] result = concatenate(arrayToMerge);
+        return getNumberOfOccurrences(result, valueToEvaluate);
+    }
+
+
+    public T getMostCommonFromMerge(T[] arrayToMerge) {
+        T[] mergedArray = concatenate(arrayToMerge);
+        Integer count = 0;
+        T result = null;
+        for(T item : mergedArray){
+            int n = getNumberOfOccurrences(mergedArray, item);
+            if(n > count){
+                count = n;
+                result = item;
+            }
+        }
+        return result;
+    }
+
+
+    public T[] removeValue(T valueToRemove) {
+        int newSize = inputArray.length - getNumberOfOccurrences(valueToRemove);
+        T[] outPutArray = Arrays.copyOf(this.inputArray, newSize);
+        int outPutIndex = 0;
+        for (T item : this.inputArray) {
+            if (!item.equals(valueToRemove)) {
+                outPutArray[outPutIndex] = item;
+                outPutIndex++;
+            }
+        }
+        return outPutArray;
+    }
+
 }
+
+/** My orginal solutions to these problems involved converting an array to an arraylist and back to an array.
+ * This posed an issue when attempting to solve the problems with generics. Generics are covariant. Meaning
+ * at compile time an array requires a known type value. Whereas generics do not. Therefore, it is not
+ * possible to instantiate a generic array. As a result, I went down a rabbit hole  attempting to instantiate a
+ * generic array inside .toArray(). Uugh, reflection and yada yada. In the end the solution involved declaring a
+ * property of type T[] and then setting that value in the constructor. So now the generic array is instantiated
+ * outside of the class. When you use arrays.copyOf it doesn't care about the type...this method just looks at
+ * the memory and makes a copy of it. No need to convert an arraylist to an array and try to instantiate it.*/

src/test/java/com/zipcodewilmington/arrayutility/RemoveValueTest.java

@@ -1,7 +1,8 @@
 package com.zipcodewilmington.arrayutility;
 
-import com.zipcodewilmington.UnitTestingUtils;
+//import com.zipcodewilmington.UnitTestingUtils;
 import org.junit.Test;
+import org.junit.Assert;
 
 /**
  * Created by leon on 3/1/18.