Array utils

Author: deepak-malik

src/com/deepak/data/structures/Utils/ArrayUtils.java

@@ -4,6 +4,8 @@
  */
 package com.deepak.data.structures.Utils;
 
+import java.lang.reflect.Array;
+
 /**
  * Utilities for Arrays
  * 
@@ -18,24 +20,104 @@ public class ArrayUtils {
 	 * @return
 	 */
 	public static <T> boolean isEmpty(T[] array) {
-		return false; // TODO
+		return array == null || array.length == 0;
+	}
+
+	/**
+	 * Method to convert array to string
+	 * 
+	 * @param array
+	 * @return {@link String}
+	 */
+	public static String toString(String[] array) {
+		return String.join(",", array);
+	}
+
+	/**
+	 * Method to convert stream of items to array
+	 * 
+	 * @param items
+	 * @return {@link T[]}
+	 */
+	@SafeVarargs
+	public static <T> T[] toArray(final T... items) {
+		return items;
+	}
+
+	/**
+	 * Method to clone a array
+	 * 
+	 * @param array
+	 * @return {@link T[]}
+	 */
+	public static <T> T[] clone(final T[] array) {
+		if (array == null) {
+			return null;
+		}
+		return array.clone();
+	}
+
+	/**
+	 * Method to check if two arrays are of same length
+	 * 
+	 * @param array1
+	 * @param array2
+	 * @return {@link boolean}
+	 */
+	public static boolean isSameLength(final Object[] array1, final Object[] array2) {
+		return getLength(array1) == getLength(array2);
+	}
+
+	/**
+	 * Method to get length of the array
+	 * 
+	 * @param array
+	 * @return {@link int}
+	 */
+	public static int getLength(final Object array) {
+		if (array == null) {
+			return 0;
+		}
+		return Array.getLength(array);
 	}
 
+	/**
+	 * Method to check if two arrays are of same type
+	 * 
+	 * @param array1
+	 * @param array2
+	 * @return {@link boolean}
+	 */
+	public static boolean isSameType(final Object array1, final Object array2) {
+		if (array1 == null || array2 == null) {
+			throw new IllegalArgumentException("The Array must not be null");
+		}
+		return array1.getClass().getName().equals(array2.getClass().getName());
+	}
+
+	/**
+	 * Method to do a binary search on int array
+	 * 
+	 * @param array
+	 * @param size
+	 * @param value
+	 * @return {@link int}
+	 */
 	public static int binarySearch(int[] array, int size, int value) {
 		int lo = 0;
-        int hi = size - 1;
-        while (lo <= hi) {
-            final int mid = (lo + hi) >>> 1;
-            final int midVal = array[mid];
-            if (midVal < value) {
-                lo = mid + 1;
-            } else if (midVal > value) {
-                hi = mid - 1;
-            } else {
-                return mid;  // value found
-            }
-        }
-        return ~lo;  // value not present
+		int hi = size - 1;
+		while (lo <= hi) {
+			final int mid = (lo + hi) >>> 1;
+			final int midVal = array[mid];
+			if (midVal < value) {
+				lo = mid + 1;
+			} else if (midVal > value) {
+				hi = mid - 1;
+			} else {
+				return mid;
+			}
+		}
+		return ~lo;
 	}
 
 }

test/com/deepak/data/structures/Utils/ArrayUtilsTest.java

@@ -0,0 +1,71 @@
+/**
+ * Data-Structures-In-Java
+ * ArrayUtilsTest.java
+ */
+package com.deepak.data.structures.Utils;
+
+import org.junit.Assert;
+import org.junit.Test;
+
+/**
+ * Test cases for array utilities
+ * 
+ * @author Deepak
+ */
+public class ArrayUtilsTest {
+
+	/**
+	 * Test case to check if array is empty
+	 */
+	@Test
+	public void testIsEmpty() {
+		String[] strArray = {};
+		Assert.assertTrue(ArrayUtils.isEmpty(strArray));
+		Integer[] intArray = {1, 2};
+		Assert.assertFalse(ArrayUtils.isEmpty(intArray));
+	}
+
+	/**
+	 * Test case to check toString for array
+	 */
+	@Test
+	public void testToString() {
+		String[] strArray = {"Apple", "Ball", "Cat", "Dog"};
+		Assert.assertEquals(ArrayUtils.toString(strArray), "Apple,Ball,Cat,Dog");
+	}
+
+	/**
+	 * Method to test cloning of array
+	 */
+	@Test
+	public void testClone() {
+		String[] strArray = {"Apple", "Ball", "Cat", "Dog"};
+		String[] newArray = ArrayUtils.clone(strArray);
+		Assert.assertTrue(strArray.length == newArray.length);
+	}
+
+	/**
+	 * Method to test if two arrays are of same length
+	 */
+	@Test
+	public void testIsSameLength() {
+		String[] array1 = {"A", "B", "C"};
+		String[] array2 = {"X", "Y", "Z"};
+		Assert.assertTrue(ArrayUtils.isSameLength(array1, array2));
+		String[] array3 = {"A", "B", "C"};
+		String[] array4 = {"X", "Y"};
+		Assert.assertFalse(ArrayUtils.isSameLength(array3, array4));
+	}
+
+	/**
+	 * Method to test if two arrays are of same type
+	 */
+	public void testIsSameType() {
+		String[] array1 = {"A", "B", "C"};
+		String[] array2 = {"X", "Y", "Z"};
+		Assert.assertTrue(ArrayUtils.isSameType(array1, array2));
+		Integer[] array3 = {1, 2, 3};
+		Assert.assertFalse(ArrayUtils.isSameType(array1, array3));
+	}
+
+}

test/com/deepak/data/structures/Utils/CollectionUtilsTest.java

@@ -0,0 +1,5 @@
+package com.deepak.data.structures.Utils;
+
+public class CollectionUtilsTest {
+
+}