473,226 Members | 1,532 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes and contribute your articles to a community of 473,226 developers and data experts.

How to Use Named Arguments

ADezii
8,834 Expert 8TB
When a call is made to a Sub or Function Procedure, you can supply Arguments in the exact order they appear in the Procedure's definition, or you can supply them in any position by name. To illustrate this point, I'll use a fictitious Function called fCalculateInterest() which accepts 3 Arguments (Currency, Single, and Long) and returns a value of type Currency.
Expand|Select|Wrap|Line Numbers
  1. Public Function fCalculateInterest(curPrincipal As Currency, sngRate As Single, lngTermInMonths As Long) As Currency
  2.   fCalculateInterest = curPrincipal * sngRate * lngTermInMonths
  3. End Function
  4.  
A simple Call to this Function would be:
Expand|Select|Wrap|Line Numbers
  1. Dim curInterest As Currency
  2. curInterest = fCalculateInterest(100000,.0725, 240)
  3.  
The above Function was called by supplying its Arguments in the correct positions, each delimited by a comma. If the positions of the Arguments change, you may either get a Data Type mismatch Error, or erroneous results. By the use of Named Arguments, you can supply the Arguments by name without any regard to position. A Named Argument consists of an Argument name followed by by a Colon and an Equal Sign (:=). We will now call that very same Function but this time reversing the positions of Arguments:
Expand|Select|Wrap|Line Numbers
  1. Dim curInterest As Curremcy
  2. curInterest = fCalculateInterest(lngTermInMonths:=240, sngRate:=.0725, curPrincipal:=100000)
  3.  
Named Arguments are extremely useful when you are calling a Procedure that has Optional Arguments. If you use Named Arguments, you don't have to include commas to denote missing position Arguments, if you don't use them, you must. The following Sub Procedure will illustrate my point, It accepts 4 Arguments, 3 of which are Optional (String, Long, Boolean).
Expand|Select|Wrap|Line Numbers
  1. Private Sub TestArgs(Arg1 As Integer, Optional Arg2 As String, Optional Arg3 As Long, Optional Arg4 As Boolean)
  2. End Sub
  3.  
A typical call to this Sub Procedure would be as follows:
Expand|Select|Wrap|Line Numbers
  1. Call TestArgs(1234, "Argument2", 999999, False)
  2.  
If you wanted to call TestArgs without passing the 2nd and 3rd Optional Arguments, and without using Named Arguments, the syntax would be:
Expand|Select|Wrap|Line Numbers
  1. Call TestArgs(1234,,,False)
If you wanted to call TestArgs without passing the 2nd and 3rd Optional Arguments, and use Named Arguments, without regard to the positions of the Arguments, the syntax would be:
Expand|Select|Wrap|Line Numbers
  1. Call TestArgs(Arg4:=False, Arg1:=1234)
NOTE: As a more realistic and practical example, and as suggested by Mary, I've included an example using the popular SendObject() Method. All Arguments of this method were used, except [TemplateFile], and their standard positions within this Method were modified. This was only possible by using this weeks Tip, Named Arguments:
Expand|Select|Wrap|Line Numbers
  1. DoCmd.SendObject OutputFormat:=acFormatXLS, ObjectName:="tblEmployeePFD", _
  2. ObjectType:=acSendTable, Subject:="Named Arguments", Bcc:="Joe Dunn", _ 
  3. To:="Tom Jones", CC:="Chris Myers", EditMessage:=False, _ MessageText:="Demonstration of the Usage of Named Arguments"
  4.  
The morale of the story is: Is is very advantageous to use Named Arguments, especially when utilizing Optional Arguments.
Nov 5 '07 #1
2 12439
missinglinq
3,532 Expert 2GB
Most useful info, ADezii, for two reasons!

First, there's all those functions that have a gazillion arguments, while usually only requiring

1 gazillion - (1 gazillion - 3) of those arguments!

And secondly, while it may take a nanosecond or two longer to enter the code, you can tell at a glance what the utilized parameters were used for! Far less cryptic!

Linq ;0)>
Nov 12 '07 #2
ADezii
8,834 Expert 8TB
Most useful info, ADezii, for two reasons!

First, there's all those functions that have a gazillion arguments, while usually only requiring

1 gazillion - (1 gazillion - 3) of those arguments!

And secondly, while it may take a nanosecond or two longer to enter the code, you can tell at a glance what the utilized parameters were used for! Far less cryptic!

Linq ;0)>
Glad you like it Linq, one of my Favorites.
Nov 13 '07 #3

Sign in to post your reply or Sign up for a free account.

Similar topics

1
by: Fuzzyman | last post by:
A colleague and I have built a Validator object for use with ConfigObj and other general schema situations. A config file is used to store a schema that specifies how to test a value that it is...
2
by: Fuzzyman | last post by:
Sorry if this is a duplicate - I use the google interface and sometiems it screws up (not showing stuff you've posted *or* not posting it). Before you ask it's because at work I have no NNTP and...
48
by: Adam Ruth | last post by:
Hello, Has there ever been any talk to adding named parameters to C? I enjoy using them in my Python and Ada code and can see their usefulness in C. I can envision an implementation where the...
5
by: Booted Cat | last post by:
I've seen lots of discussions on the proposed inclusion of "function call with named arguments" to C/C++ on these newsgroups. My proposal is slightly different in that: * No ANSI approval is...
17
by: Ben R. | last post by:
I'm reading about attribute classes and specifically, named versus positional parameters. Was this implimented instead of multiple constructors for flexibility or is there another reason I'm...
3
by: Adam Hartshorne | last post by:
What is named parameter mechanism? Any ideas? I am looking through some code and there is a comment saying "VC++ has trouble with the named parameters mechanism", which i have no idea what this...
36
by: Pacific Fox | last post by:
Hi all, haven't posted to this group before, but got an issue I can't work out... and hoping to get some help here ;-) I've got a base object that works fine with named arguments when called...
2
by: Ramashish Baranwal | last post by:
Hi, I need to process few out of a variable number of named arguments in a function and pass the remaining to another function that also takes variable number of named arguments. Consider this...
2
by: fahad.usman | last post by:
I am making an application in which if the second instance of the same application is launched, it checks its command-line arguments and passes them to the already running instance. I have been...
1
isladogs
by: isladogs | last post by:
The next online meeting of the Access Europe User Group will be on Wednesday 6 Dec 2023 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). In this month's session, Mike...
0
by: VivesProcSPL | last post by:
Obviously, one of the original purposes of SQL is to make data query processing easy. The language uses many English-like terms and syntax in an effort to make it easy to learn, particularly for...
0
by: jianzs | last post by:
Introduction Cloud-native applications are conventionally identified as those designed and nurtured on cloud infrastructure. Such applications, rooted in cloud technologies, skillfully benefit from...
0
by: abbasky | last post by:
### Vandf component communication method one: data sharing ​ Vandf components can achieve data exchange through data sharing, state sharing, events, and other methods. Vandf's data exchange method...
2
by: jimatqsi | last post by:
The boss wants the word "CONFIDENTIAL" overlaying certain reports. He wants it large, slanted across the page, on every page, very light gray, outlined letters, not block letters. I thought Word Art...
0
by: fareedcanada | last post by:
Hello I am trying to split number on their count. suppose i have 121314151617 (12cnt) then number should be split like 12,13,14,15,16,17 and if 11314151617 (11cnt) then should be split like...
0
by: stefan129 | last post by:
Hey forum members, I'm exploring options for SSL certificates for multiple domains. Has anyone had experience with multi-domain SSL certificates? Any recommendations on reliable providers or specific...
0
Git
by: egorbl4 | last post by:
Скачал я git, хотел начать настройку, а там вылезло вот это Что это? Что мне с этим делать? ...
0
by: MeoLessi9 | last post by:
I have VirtualBox installed on Windows 11 and now I would like to install Kali on a virtual machine. However, on the official website, I see two options: "Installer images" and "Virtual machines"....

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.