MC-Basic:SUB ... END SUB
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The Sub and End Sub keywords are used to delimit a subprogram within a task. The subprogram(s) must appear after the main section of the code (delimited by PROGRAM..END PROGRAM). Local variables, defined using only DIM, appear after the Sub keyword, but before the code. Subprograms are executed using the CALL keyword.
<name> is the subroutine name.
<type_1> to <type_n> are the types of the parameters.
<p_1> to<p_n> are the names of the parameters passed to the subroutine. Parameters are variables used inside the subroutine code; when the subroutine is called, the values of the variables are replaced by the calling values. By default, parameters are passed by reference. {ByVal} is an option to specify that the parameter is passed by value.
{local variables declaration} declares variables local to the subroutine.
{subroutine code} defines the algorithm to compute the returned value. Subroutines may be recursive.
Arrays can only be passed by reference. If you try to pass a whole array by value, the translator returns an error. The syntax for an array is:
SUB <name> ({<p_1>([*])+ as <type_1>}…{, <p_n>([*])+ as <type_n>})
{ local variable declaration }
{ subroutine code }
END SUB
where
<p_l> : name of array variable
<p_n>: name of array variable
[*] : dimension of array without specifying the bounds of it
+ : means one or more
Syntax
SUB <subprogram name>
<subroutine code to execute>
END SUB
SUB <name> ({ {ByVal} <p_1> As <type_1>}…{, {ByVal} <p_n> As <type_n>})
{local variable declaration}
{subroutine code}
END SUB
Calling the subroutine:
<name>( <p_1>, ... ,<p_n> )
In case there are zero arguments, the parentheses will be empty.
Availability
All versions
Type
Parmeters: Long, Double, String, Joint, Location, user defined structures, Generic Axis, Generic Group, Moving Frame (by reference only), Cam (by reference only), Comp (by reference only), Semaphore (by reference only), user defined Error and Note (by reference only).
Default
Scope Task
Limitations
Arrays are passed only by reference.
Examples
DIM SHARED lastloop as LONG
PROGRAM
lastloop=10
Attach a1
Move a1 100
Call a1_Move(LastLoop)
END PROGRAM
SUB a1_Move(lastLoop as Long) 'Pass parameters by reference
DIM Index as LONG
For Index = 1 to lastloop
Move a1 1 abs = 0
Next Index
END SUB
Array Example:
SUB mean(x[*][*] as DOUBLE, TheMean[*] as LONG)
DIM sum as DOUBLE
DIM I as LONG
FOR i = 1 to 100
sum = sum + x[i][1]
NEXT i
TheMean[1] = sum/100
END SUB