Creating and Using an Array in C#
Working with Arrays in C# is simpler and less error-prone than C and C++. Arrays in C# are objects that support the properties shown in Table 4-8.
| Property Name | Description |
|---|---|
| Length | Returns the number of elements in the array. If the array is multidimensional, it returns the total number of elements in all dimensions. |
| Rank | Returns the number of dimensions of the array, that is, the rank will be 2 for a 2D array. |
The C# array class contains the methods shown in Table 4-9.
| Method Name | Description |
|---|---|
| Clear | Sets a range of elements in the array to zero or a null reference. |
| Copy | Copies a portion of one array to another (deep copy). |
| Clone | Returns another reference to the array (a shallow copy). |
| GetLowerBound | Returns the lower bound of a specified dimension of the array. |
| GetUpperBound | Returns the upper bound of a specified dimension of the array. |
| GetValue | Returns the value at a specified index (or indexes in a multidimensional array) in an array. You can also use the index [] operator for this. |
| SetValue | Sets the value at a specified index (indices) you can also use the index “[]” operator for this |
| IndexOf | Returns the first occurrence of a specified value in a one-dimensional array. |
| LastIndexOf | Returns the last occurrence of a specified value in a one-dimensional array. |
| Reverse | Reverses the order of the elements in a one-dimensional array. |
| Sort | Sorts the elements in a one-dimensional array. (Each element must support the IComparable interface.) |
As you can see from looking at the methods and properties supported by the array class, arrays are full-featured collections in C#. You can perform a shallow or deep copy, search for the first or last occurrence of a specified value, reverse the order of the elements in the array, or sort the elements in the array. Using an array is similar to the way that you would use an array in C++. The following code demonstrates how to use arrays in C#:
namespace ArrayApp
{
using System;
using System.Text;
internal class Employee
{
public Employee(string name)
{
this.name=name;
}
public string name;
}
public class TestArray
{
public static int Main(string[] args)
{
// An array of value types
int[] intArray=new int[20];
// An array of reference types
Employee[] empArray=new Employee[2];
// An initialized array
string[] strArray= {"A", ".NET","Primer"};
int i;
for (i=0;i<20;i++)
intArray[i]=i;
empArray[0]=new Employee("Alan Gordon");
empArray[1]=new Employee("Tamber Gordon");
Console.WriteLine(intArray[1]);
Console.WriteLine(strArray[1]);
Console.WriteLine(empArray[1].name);
return 0;
}
}
}
You can also create multidimensional arrays in C#. The following example program demonstrates how to declare and use multidimensional arrays:
namespace ArrayApp
{
using System;
using System.Text;
internal class Employee
{
public Employee(string name)
{
this.name=name;
}
public string name;
}
public class TestArray
{
public static int Main(string[] args)
{
float[,,] fltArray=new float[2,3,4];
Employee[,] empArray=new Employee[2,3];
string[,] strArray= {
{"A", ".NET","Primer"},
{"COM","COM+","Primer"}};
int i, j, k;
for (i=0;i<2;i++)
for (j=0;j<3;j++)
for (k=0;k<3;k++)
fltArray[i,j,k]=
i*1.5f+2.5f*j+3.5f*k;
empArray[0,1]=new Employee("Alan Gordon");
empArray[1,1]=new Employee("Tamber Gordon");
Console.WriteLine(fltArray[1,1,1]);
Console.WriteLine(strArray[1,2]);
Console.WriteLine(empArray[1,1].name);
return 0;
}
}
}