AutoIT Example 3. Two-Dimensional Array

Code:

$letter[0][0] = "w"
$letter[0][1] = "x"
$letter[1][0] = "y"
$letter[1][1] = "z"

A visual representation of Example 3 would be a 2×2 matrix as displayed in Figure 1.

AutoIT Constants and Arrays

Constants

 A constant is a variable that never changes. It remains a static value for the entire
script execution. You cannot change the value of a constant, nor can you convert
an existing variable into a constant. Placing Const after Dim, Global or Local makes
the variable a constant. You can also declare a constant variable without explicit
declaration. The following example illustrates how to declare a constant variable
in each scenario:

Code:

Const $example = 0
Dim Const $example1 = 1
Global Const $example2 = 2
Local Const $example3 = 3

Arrays

 An array is a matrix of data in which all the elements are of the same data type and
size. For example, an array of two numbers—“5” and “3”—is declared as follows:

Code:

$num[0] = "5"
$num[1] = "3"

Figure 1. Visual representation of Example 3. Two-Dimensional Array.
Arrays can also be multidimensional, with up to 64 dimensions. Example 3 shows a two-dimensional array.

AutoIT Variable Types

Dim, Global, and Local

There are three types of variables in AutoItT:

Dim

  Declaring a variable using Dim gives it the scope of its current location within   the script. If the variable is declared outside any functions, its scope is global.

  The following is an example of declaring a Dim variable in the global scope. It

runs setup.exe in the directory where the script is located:

Code:

Dim $variable = @ScriptDir & "\setup.exe"
  Run($variable)

  The next example shows how declaring a Dim variable inside a function allows it only Local scope and how the variable is destroyed once the function is complete.

 The result is a script that errors out when run because $variable is not declared globally:

Code:

function()
  Func function()
    Dim $variable = @ScriptDir & "\setup.exe"
  EndFunc

  Run($variable)

 You should explicitly declare variables as Global or Local to avoid problems. If a Dim variable is declared inside a function but a Global variable already exists, the Global variable is overwritten. The following example shows what happens if a Global variable exists when the same variable is declared as Dim within a

function. The result is that setupbad.exe runs instead of setup.exe; the Global $variable is modified to setupbad.exe because Dim was used to declare the variable locally within the function:

Code:

Global $variable = @ScriptDir & "\setup.exe"
  function()

  Func function()
    Dim $variable = @ScriptDir & "\setupbad.exe"
  EndFunc

  Run($variable)

Global

  This type of variable can be read from or written to from anywhere in the script.

Global variables can be used in functions without being destroyed when the

functions complete. The following is an example of declaring a Global variable:

Code:

  Global $variable = 2

Local

 A Local variable is used in the scope of a function. Once the function is complete,the variable is destroyed. If a Global variable of the same name already exists, the function modifies the Global variable and it is not destroyed when

the function completes. Variables are always checked in the local scope first,

then in the global scope. The following example shows the use of a Local variable

within a function:

Code:

function()
  Func function()
    Local $variable = @ScriptDir & "\setup.exe"
    Run($variable)
  EndFunc

AutoIT: Variables and Includes

A variable is simply a named placeholder for a string or array of data. You can use a variable as many times as you need within a script and it only requires declaration once. This allows you to manage and manipulate data in a centralized location if desired.

Variables are a necessity if you want to write robust scripts that are fairly simple to modify. For example, defining a filename as a variable allows you to change the filename from a single location instead of changing many static entries. (Using static data entries can lead to problems.) Example 1 installs two Windows XP Security updates. Example 2 performs the same operations, but does so using

variables. You may not yet understand everything displayed in the examples; they are only meant to show that replacing filenames with variables is one way to simplify your code.

AutoIT Example 1. Windows Update Automation

Code:

If @Username <> "Administrator" Then
RunAsSet("Administrator",@ComputerName,"password")
    install()
    RunAsSet()
  Else
    install()
  EndIf

Func install()
    RunWait("Windows Update 1.exe /passive /norestart")
    RunWait("Windows Update 2.exe /passive /norestart")
EndFunc