Arrays

Array is a collection of similar data which is stored in continuous memory addresses. Array values can be fetched using index.

Index starts from 0 to size-1.

Arrays can be one-dimensional or multi-dimensional in VB.net language. The more popular and frequently used arrays are one-dimensional and two-dimensional arrays.

Arrays store the collection of data sequentially in memory and they must share same data type.

How to declare an array?

Dim array-name as Datatype  = {values}

Example

Dim num(10) As Integer	'an array of 11 integers

Dim matrix(4, 4) As Integer	'2-D array of integers

Dim directions() As String = {"East", "West", "North", "South"} 'An array of 4 string elements 

How to access array elements

Array elements can be accessed by using indices. Array indices starts from 0. Array(n-1) can be used to access nth element of an array.

Example

One-Dimensional Array Example

Public Module Arrays
	Public Sub Main(args() As string)
		Dim directions() As String = {"East", "West", "North", "South"} 
    Dim i as integer = 0
    For i = 0 To 3
         Console.WriteLine(directions(i))
         Next i
    Console.ReadKey()
   End Sub
End Module

Check result here

Two-Dimensional Array Example

Public Module Arrays
	Public Sub Main(args() As string)
		Dim matrix( , ) As Integer = {{1,2}, {3,4},{5,6}} 
    Dim i, j as integer = 0
    
    For i = 0 To 2
      For j = 0 To 1
        Console.WriteLine("matrix[{0}, {1}] = {2}", i, j, matrix(i, j))
        Next j
      Next i     
    
    Console.ReadKey()
   End Sub
End Module

Check result here

Summary

  • Arrays is a collection of homogeneous data.
  • Arrays stores data sequentially in memory.
  • Arrays are finite.