#include <Array.au3>

Local $data[14] = [4,5,2,3,0,1,7,6,9,8,12,11,10,13]
Local $2D_array[8][7] ; This array is needed for another process.

; The 1st column is a key which determines the number of entries in each row.
; Numbers in this 1st column are excluded from the search results.
$2D_array[2][0] = 1
$2D_array[3][0] = 1
$2D_array[4][0] = 6
$2D_array[5][0] = 2
$2D_array[6][0] = 3
$2D_array[7][0] = 1

; Populate the remaining columns of the 2D array.
$a = 0
For $i = 2 To 7
    For $j = 1 To $2D_array[$i][0]
        $2D_array[$i][$j] = $data[$a]
        $a += 1
    Next
Next

; NONE OF THE CODE ABOVE CAN NOT BE ALTERED.

; Breakng convention.
Local $index_matching_array[14] ; Array created to avoid testing many empty cells during the search (for sparce population in a large array).
$a = 0
For $i = 2 To 7
    For $j = 1 To $2D_array[$i][0]
        $index_matching_array[$a] = $i
        $a += 1
    Next
Next

find()

Func find()
    Local $x = Random(0,13,1) ; Whatever element we want to find in the 2D array.
    Local $data_index = _ArraySearch($data, $x, 0, 0, 0, 1) ; This search will be repeated thousands of times.
    Local $return_value = $index_matching_array[$data_index]
    ; Display result =>
    MsgBox(0, "Index in 2D_array", $x & " was found at " & @CRLF & "array index " & $return_value)
    _ArrayDisplay($2D_array)
EndFunc

#include <GUIConstantsEx.au3>

; Create a GUI so that there are multiple GUIs in the script
$hGUI_2 = GUICreate("Test 2", 200, 100, 10, 10) ; <<<<<<<<<<<<<<<<<<<<
ConsoleWrite("GUI_2 = " & $hGUI_2 & @CRLF) ; <<<<<<<<<<<<<<<<<<<<
GUISetState(@SW_SHOW, $hGUI_2) ; <<<<<<<<<<<<<<<<<<<<

; Create the main GUI
$hGUI_1 = GUICreate("Test 1", 200, 100, 300, 10)
ConsoleWrite("GUI_1 = " & $hGUI_1 & @CRLF)

; Create first control
$hButton_1 = GUICtrlCreateButton("Test 1", 10, 10, 80, 30)

; Simulate the StringSize UDF
_Sim_StringSize()

; Switch to the dummy GUI
ConsoleWrite("Switch [?] - 2 (last was GUI_3): " & GUISwitch($hGUI_2) & @CRLF) ; xxxxxxxxxxxxxxxxxxx

; Switch back to the main GUI
ConsoleWrite("Switch 2 - 1 (should be GUI_2): " & GUISwitch($hGUI_1) & @CRLF) ; xxxxxxxxxxxxxxxxxxx

; Create second control in the main GUI
$hButton_2 = GUICtrlCreateButton("Test 2", 10, 50, 80, 30)

GUISetState(@SW_SHOW, $hGUI_1)

While 1
    Switch GUIGetMsg()
        Case $GUI_EVENT_CLOSE
            Exit
    EndSwitch
WEnd

Func _Sim_StringSize()
    $hGUI_3 = GUICreate("Test 3", 200, 100, 600, 10)
    ConsoleWrite("GUI_3 = " & $hGUI_3 & @CRLF)
    GUISetState(@SW_SHOW, $hGUI_3)
    GUIDelete($hGUI_3)
EndFunc