Executing Sub and Function Procedures
Although you may not know much about developing procedures at this point, I’m going to jump ahead a bit and discuss how to execute these procedures.
This is important because these procedures are worthless unless you know how to execute it.
Executing Sub procedure
Sub procedure means the same thing as running or calling a
You can use whatever terminology you like.
You can execute a
VBA Sub in many ways - that’s one reason you can do so many useful things with
Here’s a list of the ways to execute a
- With the
Run -> Run Sub/UserFormcommand (in the
Sub procedurein which the cursor is located. This menu command has two alternatives: the
F5key and the
Run Sub/UserFormbutton on the Standard toolbar in the
VBE. These methods don’t work if the procedure requires one or more arguments.
- From another
Sub procedurethat you write.
- From a custom item on the ribbon you develop.
- From the
Immediate windowin the
VBE. Just type the name of the
Sub procedureand press
RunMacro -> Select Macro you want to run. By this, your macro runs the
Sub procedurewithout opening
I demonstrate some of these techniques in the following sections.
Before I can do that, you need to enter a
Sub procedure into a
VBA module as suggested below:
- Open the VBE in Solidworks.
- Enter the following code into your module
Sub CubeRoot() Number = InputBox("Enter a positive number.") MsgBox number ^ (1/3) & "is the cube root." End Sub
This procedure asks the user for a number and then displays that number’s cube root in a
Below Figures shows what happens when you execute this procedure.
I entered 4 as input value. And get result as shown in below image.
By the way,
CubeRoot is not an example of a good macro. It doesn’t check for errors, so it fails easily.
To see what I mean, try clicking the
Cancel button in the input box or entering a negative number.
Executing the Sub procedure directly
The quickest way to execute this procedure is by doing so directly from the VBA module in which you defined it.
Follow these steps:
- Activate the
VBEand select the
VBA modulethat contains the procedure.
- Move the cursor anywhere in the procedure’s code.
Run -> Run Sub/UserForm).
- Respond to the input box and click
- The procedure displays the
cube rootof the number you entered.
You can’t use the
Run -> Run Sub/UserForm command to execute a
Sub procedure that uses arguments, because you have no way to pass the arguments to the procedure.
If the procedure contains one or more arguments, the only way to execute it is to call it from
another procedure — which must supply the argument(s).
Executing the Sub procedure from another procedure
You can also execute a
Sub procedure from another procedure.
Follow these steps if you want to give this a try:
- Activate the
VBAmodule that holds the
Enter this new procedure (either above or below
CubeRootcode — it makes no difference):
Sub NewSub() Call CubeRoot End Sub
- Execute the NewSub macro.
The easiest way to do this is to move the cursor anywhere within the
NewSub code and press
Notice that this NewSub procedure simply executes the CubeRoot procedure.
Please note that the keyword
Callis optional. The statement can consist of only the Sub procedure’s name. I find that using the
Callkeyword makes it perfectly clear that a procedure is being called.
Executing Function procedure
Function procedures, unlike
Sub procedures, can be only executed in only one way:
- By calling the function from another
Try this simple function. Enter it into a VBA module:
Function CubeRoot() CubeRoot = number ^ (1/3) End Function
This function is pretty bored — it merely calculates the cube root of the number passed to it as its argument.
It does provide a starting point for understanding
It also presents an important concept about functions: how to return the value.
(You do remember that a function returns a value, right?)
Notice that the single line of code that makes up this
Function procedure performs a calculation.
The result of the math (number to the power of 1⁄3) is assigned to the variable
CubeRoot is also the name of the function.
To tell the function what value to return, you assign that value to the name of the function.
Executing the Function procedure from a Sub procedure
Because you can’t execute a
function directly, you must call it from another procedure.
Enter the following simple procedure in the same
VBA module that contains the
Sub CubeRoot() Ans = CubeRoot(125) MsgBox Ans End Sub
When you execute the
CubeRoot procedure (using any of the methods described earlier), Youe software displays a message box that contains the value of the
Ans variable, which is 5.
Here’s what’s going on:
CubeRootreceive argument of 125.
Function CubeRoot(number)is executed. As described previously, number is an argument. And here the value of this is 125.
- Then by number ^ (1/3) we get the cube of 125. (why? Because 125 is argument passed by the
subfunction and this 125 is the value of number.)
- After that cube value of 125, i.e. 5, is assigned to or given to or equal to
CubeRootassigned to or given to or equal to
Ans. After that message boxes show the value of 5 in your screen.
Please read again if you don’t understand what is going on here.
Next post will be about Programming Concepts, Comments and Data-types.