PROCname(expression, ...)

Calls a procedure defined with DEF PROCname(...) ... ENDPROC.
A procedure performs actions and then returns to the statement after the call. It does not return a value.

Remarks: There is no space between PROC and the name.; Example: PROCdrawBox(10, 5) not PROC drawBox(10, 5).

The number and types of arguments must match the DEF PROC... definition.
Procedures cannot be used inside expressions. For a value, define and call an FN function.

Examples

Define and call a procedure

DEF PROChello(NAME$)
    PRINT "Hello, "; NAME$
ENDPROC
 
PROChello("WORLD")

Procedure that draws using parameters

DEF PROCfilledCircle(X, Y, R, COL)
    GCOL COL
    CIRCLE X, Y, R, TRUE
ENDPROC
 
PROCfilledCircle(160, 120, 40, RGB(0,255,0))

Locals inside a procedure

DEF PROCsumDemo(N)
    LOCAL TOTAL = 0
    FOR I = 1 TO N
        LOCAL TOTAL = TOTAL + I
    NEXT
    PRINT "Sum to "; N; " = "; TOTAL
ENDPROC
 
PROCsumDemo(5)

Errors and behaviour

Calling an undefined procedure, using the wrong number of arguments, or mismatched types raises a runtime error (trap with ON ERROR PROC... if desired).
The end of a procedure is marked by ENDPROC. Using ENDPROC outside a procedure is an error.
Parameters are available by name inside the body. Use LOCAL name = expr to create or update locals that shadow any globals of the same name.

See also:
DEF · ENDPROC · FN · LOCAL