Closes #63.

Author: Konard

csharp/Platform.Collections.Tests/ArrayTests.cs

@@ -0,0 +1,24 @@
+using Xunit;
+using Platform.Collections.Arrays;
+
+namespace Platform.Collections.Tests
+{
+    public class ArrayTests
+    {
+        [Fact]
+        public void GetElementTest()
+        {
+            var nullArray = (int[])null;
+            Assert.Equal(0, nullArray.GetElementOrDefault(1));
+            Assert.False(nullArray.TryGetElement(1, out int element));
+            Assert.Equal(0, element);
+            var array = new int[] { 1, 2, 3 };
+            Assert.Equal(3, array.GetElementOrDefault(2));
+            Assert.True(array.TryGetElement(2, out element));
+            Assert.Equal(3, element);
+            Assert.Equal(0, array.GetElementOrDefault(10));
+            Assert.False(array.TryGetElement(10, out element));
+            Assert.Equal(0, element);
+        }
+    }
+}

csharp/Platform.Collections.Tests/ListTests.cs

@@ -0,0 +1,26 @@
+using System.Collections.Generic;
+using Xunit;
+using Platform.Collections.Lists;
+
+
+namespace Platform.Collections.Tests
+{
+    public class ListTests
+    {
+        [Fact]
+        public void GetElementTest()
+        {
+            var nullList = (IList<int>)null;
+            Assert.Equal(0, nullList.GetElementOrDefault(1));
+            Assert.False(nullList.TryGetElement(1, out int element));
+            Assert.Equal(0, element);
+            var list = new List<int>() { 1, 2, 3 };
+            Assert.Equal(3, list.GetElementOrDefault(2));
+            Assert.True(list.TryGetElement(2, out element));
+            Assert.Equal(3, element);
+            Assert.Equal(0, list.GetElementOrDefault(10));
+            Assert.False(list.TryGetElement(10, out element));
+            Assert.Equal(0, element);
+        }
+    }
+}

csharp/Platform.Collections/Arrays/GenericArrayExtensions.cs

@@ -8,6 +8,42 @@ namespace Platform.Collections.Arrays
 {
     public static class GenericArrayExtensions
     {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T GetElementOrDefault<T>(this T[] array, int index) => array != null && array.Length > index ? array[index] : default;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T GetElementOrDefault<T>(this T[] array, long index) => array != null && array.LongLength > index ? array[index] : default;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool TryGetElement<T>(this T[] array, int index, out T element)
+        {
+            if (array != null && array.Length > index)
+            {
+                element = array[index];
+                return true;
+            }
+            else
+            {
+                element = default;
+                return false;
+            }
+        }
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool TryGetElement<T>(this T[] array, long index, out T element)
+        {
+            if(array != null && array.LongLength > index)
+            {
+                element = array[index];
+                return true;
+            }
+            else
+            {
+                element = default;
+                return false;
+            }
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static T[] Clone<T>(this T[] array)
         {

csharp/Platform.Collections/Lists/IListExtensions.cs

@@ -8,6 +8,24 @@ namespace Platform.Collections.Lists
 {
     public static class IListExtensions
     {
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static T GetElementOrDefault<T>(this IList<T> list, int index) => list != null && list.Count > index ? list[index] : default;
+
+        [MethodImpl(MethodImplOptions.AggressiveInlining)]
+        public static bool TryGetElement<T>(this IList<T> list, int index, out T element)
+        {
+            if (list != null && list.Count > index)
+            {
+                element = list[index];
+                return true;
+            }
+            else
+            {
+                element = default;
+                return false;
+            }
+        }
+
         [MethodImpl(MethodImplOptions.AggressiveInlining)]
         public static bool AddAndReturnTrue<T>(this IList<T> list, T element)
         {