KT-22298 Improve docs for Array.copyOf(newSize: Int)

Signed-off-by: Valeriy Zhirnov <neonailol@gmail.com>

libraries/stdlib/samples/test/samples/collections/arrays.kt

@@ -17,7 +17,6 @@
 package samples.collections
 
 import samples.*
-import kotlin.test.*
 
 
 @RunWith(Enclosed::class)
@@ -76,4 +75,32 @@ class Arrays {
         }
     }
 
+    class CopyOfOperations {
+
+        @Sample
+        fun copyOf() {
+            val array = arrayOf("apples", "oranges", "limes")
+            val arrayCopy = array.copyOf()
+            assertPrints(arrayCopy.contentToString(), "[apples, oranges, limes]")
+        }
+
+        @Sample
+        fun resizingCopyOf() {
+            val array = arrayOf("apples", "oranges", "limes")
+            val arrayCopyPadded = array.copyOf(5)
+            assertPrints(arrayCopyPadded.contentToString(), "[apples, oranges, limes, null, null]")
+            val arrayCopyTruncated = array.copyOf(2)
+            assertPrints(arrayCopyTruncated.contentToString(), "[apples, oranges]")
+        }
+
+        @Sample
+        fun resizedPrimitiveCopyOf() {
+            val array = intArrayOf(1, 2, 3)
+            val arrayCopyPadded = array.copyOf(5)
+            assertPrints(arrayCopyPadded.contentToString(), "[1, 2, 3, 0, 0]")
+            val arrayCopyTruncated = array.copyOf(2)
+            assertPrints(arrayCopyTruncated.contentToString(), "[1, 2]")
+        }
+    }
+
 }