Array Index

FreeBASIC

Array Index
 
An array index is the number used to access an Array of Variables created using the Dim command.

Description

The following examples illustrate the use of array elements.

If we have an array myArray with elements of 1 to 10, filled with random data:
Index        Data
1              5
2              2
3              6
4              5
5              9
6              1
7              0
8              4
9              5
10             7

One can access each piece of data separately by pointing to the Index of the array element:
    Print myArray(5)
    

Printing the data contained in the fifth element of myArray results in an output of:
	9
	
To change the contents of an array, use it like any other Variable:
    myArray(3) = 0
    

To print the contents of myArray(3), use the command:
    Print myArray(3)
    

Which results in an output of:
	0
	
Array elements can be indexed using another Variable. In this example we set all elements in our array to zero:
    Dim a As Integer
    For a = 1 To 10
      myArray(a) = 0
    Next a
    

To change a random array element to a random value:
    Dim Index As Integer
    Dim Value As Integer
    index = Int(Rnd(1) * 10) + 1 'This line will simply return a random value between 1 and 10
    Value = Int(Rnd(1) * 10) + 1 'This line will do the same
    myArray(index) = Value
    



Example

Declare Sub PrintArray()

Dim Numbers(1 To 10) As Integer
Dim Shared OtherNumbers(1 To 10) As Integer
Dim a As Integer

Numbers(1) = 1
Numbers(2) = 2
OtherNumbers(1) = 3
OtherNumbers(2) = 4

PrintArray ()

For a = 1 To 10
 Print Numbers(a)
Next a

Print OtherNumbers(1)
Print OtherNumbers(2)
Print OtherNumbers(3)
Print OtherNumbers(4)
Print OtherNumbers(5)
Print OtherNumbers(6)
Print OtherNumbers(7)
Print OtherNumbers(8)
Print OtherNumbers(9)
Print OtherNumbers(10)

Sub PrintArray ()
 Dim a As Integer
 For a = 1 To 10
   Print otherNumbers(a)
 Next a
End Sub


See also