C# 4 and .NET 4

array Class ❘ 135
The CreateInstance() method has many overloads to create multidimensional arrays and also to create
arrays that are not 0-based. The following example creates a two-dimensional array with 2 3 elements.
The first dimension is 1-based; the second dimension is 10-based.
int[] lengths = { 2, 3 };
int[] lowerBounds = { 1, 10 };
Array racers = Array.CreateInstance(typeof(Person), lengths, lowerBounds);
Setting the elements of the array, the SetValue() method accepts indices for every dimension:
racers.SetValue(new Person
{
FirstName = "Alain",
LastName = "Prost"
}, 1, 10);
racers.SetValue(new Person
{
FirstName = "Emerson",
LastName = "Fittipaldi"
}, 1, 11);
racers.SetValue(new Person
{
FirstName = "Ayrton",
LastName = "Senna"
}, 1, 12);
racers.SetValue(new Person
{
FirstName = "Ralf",
LastName = "Schumacher"
}, 2, 10);
racers.SetValue(new Person
{
FirstName = "Fernando",
LastName = "Alonso"
}, 2, 11);
racers.SetValue(new Person
{
FirstName = "Jenson",
LastName = "Button"
}, 2, 12);
code snippet Sample1/Program.cs
Although the array is not 0-based, you can assign it to a variable with the normal C# notation. You just
have to pay attention not to cross the boundaries.
Person[,] racers2 = (Person[,])racers;
Person first = racers2[1, 10];
Person last = racers2[2, 12];
Copying arrays
Because arrays are reference types, assigning an array variable to another
one just gives you two variables referencing the same array. For copying
arrays, the array implements the interface ICloneable. The Clone()
method that is defined with this interface creates a shallow copy of the array.
If the elements of the array are value types, as in the following code
segment, all values are copied, as you can see in Figure 6-5.
int[] intArray1 = {1, 2};
int[] intArray2 = (int[])intArray1.Clone();
intArray1 1
2
intArray2 1
2
figure 6-5
www.it-ebooks.info