CRBasic Example 61. Subroutine with Global and Local Variables
'This program example demonstrates the use of global and local variables with subroutines.
'
'Global variables are those declared anywhere in the program as Public or Dim.
'Local variables are those declared in the Sub() instruction.
'Program Function: Passes two variables to a subroutine. The subroutine increments each
'variable once per second, multiplies each by pi, then passes results back to the main
'program for storage in a data table.
'Global variables (Used only outside subroutine by choice)
'Declare Counter in the Main Scan.
Public counter(2) As Long
'Declare Product of PI * counter(2).
Public pi_product(2) As Float
'Global variable (Used only in subroutine by choice)
'For / Next incrementor used in the subroutine.
Public i_sub As Long
'Declare Data Table
DataTable(pi_results,True,-1)
Sample(1,counter(),IEEE4)
EndTable
'Declare Subroutine
'Declares j(4) as local array (can only be used in subroutine)
Sub ProcessSub (j(2) As Long,OutVar(2) As Float)
For i_sub = 1 To 2
j(i_sub) = j(i_sub) + 1
'Processing to show functionality
OutVar(i_sub) = j(i_sub) * 4 * ATN(1) '(Tip: 4 * ATN(1) = pi to IEEE4 precision)
Next i_sub
EndSub
BeginProg
counter(1) = 1
counter(2) = 2
Scan(1,Sec,0,0)
'Pass Counter() array to j() array, pi_pruduct() to OutVar()
Call ProcessSub (counter(),pi_product())
CallTable pi_results
NextScan
7.9.21 TCP/IP — Details
Related Topics:
• TCP/IP — Overview (p. 91)
• TCP/IP — Details (p. 423)
• TCP/IP — Instructions (p. 593)
• TCP/IP Links — List (p. 652)
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