Sub is a procedure that performs a specific task but does not return a specific value.
Sub ProcedureName ([argument_list]) [statements] End Sub
If no access modifier is specified, a procedure is
Public by default.
Function is a procedure that is given data and returns a value, ideally without global or module-scope side-effects.
Function ProcedureName ([argument_list]) [As ReturnType] [statements] End Function
Property is a procedure that encapsulates module data. A property can have up to 3 accessors:
Get to return a value or object reference,
Let to assign a value, and/or
Set to assign an object reference.
Property Get|Let|Set PropertyName([argument_list]) [As ReturnType] [statements] End Property
Properties are usually used in class modules (although they are allowed in standard modules as well), exposing accessor to data that is otherwise inaccessible to the calling code. A property that only exposes a
Get accessor is "read-only"; a property that would only expose a
Set accessor is "write-only". Write-only properties are not considered a good programming practice - if the client code can write a value, it should be able to read it back. Consider implementing a
Sub procedure instead of making a write-only property.
Property Get procedure can (and should!) return a value to its caller. This is done by assigning the identifier of the procedure:
Property Get Foo() As Integer Foo = 42 End Property
As stated above Functions are smaller procedures that contain small pieces of code which may be repetitive inside a Procedure.
Functions are used to reduce redundancy in code.
Similar to a Procedure, A function can be declared with or without an arguments list.
Function is declared as a return type, as all functions return a value. The Name and the Return Variable of a function are the Same.
Function With Parameter:
Function check_even(i as integer) as boolean if (i mod 2) = 0 then check_even = True else check_even=False end if end Function
Function Without Parameter:
Function greet() as String greet= "Hello Coder!" end Function
The Function can be called in various ways inside a function. Since a Function declared with a return type is basically a variable. it is used similar to a variable.
call greet() 'Similar to a Procedural call just allows the Procedure to use the 'variable greet string_1=greet() 'The Return value of the function is used for variable 'assignment
Further the function can also be used as conditions for if and other conditional statements.
for i = 1 to 10 if check_even(i) then msgbox i & " is Even" else msgbox i & " is Odd" end if next i
Further more Functions can have modifiers such as By ref and By val for their arguments.