@@ -15,14 +15,16 @@ limitations under the License.
 --]]
 
 local System = System
+local throw = System.throw
 local Collection = System.Collection
 local buildArray = Collection.buildArray
 local getArray = Collection.getArray
 local setArray = Collection.setArray
-local checkIndex = Collection.checkIndex 
 local arrayEnumerator = Collection.arrayEnumerator
 local findAll = Collection.findAllOfArray
 
+local IndexOutOfRangeException = System.IndexOutOfRangeException
+
 local assert = assert
 local select = select
 local setmetatable = setmetatable
@@ -49,6 +51,13 @@ function Array.getLength(this)
   return #this
 end
 
+function Array.GetLength(this, dimension)
+  if dimension ~= 0 then
+    throw(IndexOutOfRangeException())
+  end
+  return #this
+end
+
 function Array.getCount(this)
   return #this
 end
@@ -141,13 +150,16 @@ function MultiArray.get(this, ...)
   return getArray(this, index)
 end
 
-function MultiArray.getLength(this, dimension)
-  if dimension == nil then
-    return #this
-  end
+function MultiArray.getLength(this)
+	return #this
+end
+
+function MultiArray.GetLength(this, dimension)
   local rank = this.__rank__
-  checkIndex(rank, dimension)
-  return this.__rank__[dimension + 1]
+  if dimension < 0 or dimension >= #rank then
+    throw(IndexOutOfRangeException())
+  end
+  return rank[dimension + 1]
 end
 
 function MultiArray.getRank(this)
 
@@ -118,7 +118,16 @@ define("System.ArgumentOutOfRangeException", {
   end,
 
   getActualValue = function(this) 
-      return this.actualValue
+    return this.actualValue
+  end
+})
+
+define("System.IndexOutOfRangeException", {
+   __tostring = toString,
+   __inherits__ = { Exception },
+
+   __ctor__ = function (this, message, innerException)
+    Exception.__ctor__(this, message or "Index was outside the bounds of the array.", innerException)
   end
 })
 
 
@@ -142,7 +142,7 @@ String.ToString = tostring
 
 function String.get(this, index)
   if index < 0 or index >= #this then
-      throw(IndexOutOfRangeException())
+    throw(IndexOutOfRangeException())
   end
   return sbyte(this, index + 1)
 end
 
@@ -372,3 +372,4 @@ test(testStringBuilder, "StringBuilder")
 test(testIO, "IO")
 --test(testConsole, "Console")
 --test(testAsync, "Async")
+