CALL
Statement to invoke a subroutine
Syntax:
Call procname ([parameter list])
Description:
Calls a Sub or Function.
This keyword is a holdover from earlier dialects of BASIC, and is mainly deprecated.
In -lang qb, it can be used to call subs in code before they are declared. The function will be implicitly Declare'd, with any parameters passed Byref As Any.
Note: until the function is declared, no type-checking is done on the parameters, so it is up to the programmer to ensure they are of the correct type.
This keyword is a holdover from earlier dialects of BASIC, and is mainly deprecated.
In -lang qb, it can be used to call subs in code before they are declared. The function will be implicitly Declare'd, with any parameters passed Byref As Any.
Note: until the function is declared, no type-checking is done on the parameters, so it is up to the programmer to ensure they are of the correct type.
Examples:
'' Compile with -lang qb or -lang fblite
#lang "fblite"
Declare Sub foobar(ByVal x As Integer, ByVal y As Integer)
Call foobar(35, 42)
Sub foobar(ByVal x As Integer, ByVal y As Integer)
Print x; y
End Sub
#lang "fblite"
Declare Sub foobar(ByVal x As Integer, ByVal y As Integer)
Call foobar(35, 42)
Sub foobar(ByVal x As Integer, ByVal y As Integer)
Print x; y
End Sub
'' Compile with -lang qb or -lang fblite
#lang "fblite"
Function f ( ) As Integer
f = 42
End Function
Call f ' execute function f, but ignore the answer
#lang "fblite"
Function f ( ) As Integer
f = 42
End Function
Call f ' execute function f, but ignore the answer
'' Compile with -lang qb
'$lang: "qb"
Call mysub(15, 16) '' call "mysub" before it has been declared, or even mentioned.
Sub mysub(ByRef a As Integer, ByRef b As Integer)
Print a, b
End Sub
'$lang: "qb"
Call mysub(15, 16) '' call "mysub" before it has been declared, or even mentioned.
Sub mysub(ByRef a As Integer, ByRef b As Integer)
Print a, b
End Sub
Dialect Differences:
- The use of Call is not allowed in the -lang fb dialect.
- The -lang fblite dialect does not allow you to call functions that have not been previously declared.
Differences from QB:
- The procedure must have already been declared.
- Call in QB will make a copy of all parameters, so changes made to the arguments inside the called Sub will not be reflected in the variables in the caller.
See also:
Back to Procedures
