The index of the first element of the specified dimension in the array.
Type Reason IndexOutOfRangeException dimension < 0.
-or-
dimension is equal to or greater than the Array.Rank property of the current instance.
GetLowerBound(0) returns the starting index of the first dimension of the array, and GetLowerBound(Rank - 1) returns the starting index of the last dimension of the array.
The Array.GetLowerBound(int) method always returns a value that indicates the index of the lower bound of the array, even if the array is empty.
Note that, although most arrays in the .NET Framework are zero-based (that is, the Array.GetLowerBound(int) method returns zero for each dimension of an array), the .NET Framework does support arrays that are not zero-based. Such arrays can be created with the Array.CreateInstance(Type, Int32[], Int32[]) method, and can also be returned from unmanaged code.
This method is an O(1) operation.