VBA Macros Interview Questions

1. What is the file extension of excel workbooks with macros in Excel 2003, 2007, 2010 ?


Ans: Excel 2003 = xls Excel 2007 = xlsm Excel 2010 = xlsm

2. Why we are using macros ?


Ans: If you perform a task repeatedly in Microsoft Excel, you can automate the task with a macro. Moreover, macro can perform lots of tasks which we can't do manually ( like looping statement)

3. What is the shortcut to goto VBA screen ?

Ans: ALT + F11

4. Can we record a looping statement ? Give some examples of looping statements ?

Ans: No. For loop, Do While Loop, Do Until Loop

5. How to add a module to a VBA project?

Ans: Right Click on VBA project in VBA screen > Insert > Click on Module

6. a,What is the meaning of "Option Explicit"? b, Where it should be used ?

Ans: a, Option Explicit makes the declaration of Variables Mandatory (it forces us to declare all variables used in our codes) Line explicit function makes the compiler to identify all the variables which are not specified by the dim statement. This command significantly reduces the problem of type errors. This is used extensively because VBA deals with information rich applications in which type errors are common.
b. It can be used inside a module, before starting any sub procedures

7. How we will hide a sheet permanently ? (How to hide a worksheet so that a normal user cannot unhide it)?


Ans:
Use Sheet's visible property and set it to xlSheetVeryHidden. We can do it in 2 ways.
1. VBA screen > worksheet properties > visible > change to xlSheetVeryHidden
or 2. Use code sheet1.Visible = xlSheetVeryHidden

8. a, If I require a macro to run everytime when a workbook opens, can this be recorded ?

Ans: No
b, So, where should I add codes for this ?

Ans: goto VBA screen > double click on THISWORKBOOK > then select > Workbook_Open

9. What is the difference between thisworkbook and activeworkbook?

Ans: ThisWorkbook refers to the workbook where code is being written while ActiveWorkbook refers to the workbook which is in active state with active window. In case of only one workbook open, ActiveWorkbook is same as ThisWorkbook

10. Now I have an object variable named "Wkbook", tell the code to assign the activeworkbook to this object ?


Ans: SET Wkbook = ACTIVEWORKBOOK

11. What is the difference between ByVal and ByRef and which is default ?


Ans: ByRef: If you pass an argument by reference when calling a procedure the procedure access to the actual variable in memory. As a result the variable's value can be changed by the procedure.
ByVal: If you pass an argument by value when calling a procedure the variable's value can be changed with in the procedure only outside the actual value of the variable is retained.
ByRef is default: Passing by reference is the default in VBA. If you do not explicitly specify to pass an argument by value VBA will pass it by reference.

12. What is the meaning of Option Explicit and Option Base?


Ans:

Option Explicit makes the declaration of Variables Mandatory while Option Base used at module level to declare the default lower bound for array subscripts. For eg. Option Base 1 will make the array lower bound as 1 instead of 0.

13. What are various data type and their size?


Ans:

i) The Boolean data type has only two states, True and False. These types of variables are stored as 16-bit (2 Byte) numbers, and are usually used for flags.
ii) The Byte data type is an 8-bit variable which can store value from 0 to 255.
iii) The Double data type is a 64-bit floating point number used when high accuracy is needed.
iv) The Integer data type is a 16-bit number which can range from -32768 to 32767. Integers should be used when you are working with values that can not contain fractional numbers. In case, you're working over 32767 rows use Long as data type.
v) The Long data type is a 32-bit number which can range from -2,147,483,648 to 2,147,483,647.
vi) The Single data type is a 32-bit number ranging from -3.402823e38 to -1.401298e-45 for negative values and from 1.401298e-45 to 3.402823e38 for positive values. When you need fractional numbers within this range, this is the data type to use.
vii) The String data type is usually used as a variable-length type of variable. A variable-length string can contain up to approximately 2 billion characters. Each character has a value ranging from 0 to 255 based on the ASCII character set.

14. Code to find a Last used Row in a column or Last used column of a Row.


Ans:
Last Row in a column can be find using End(xlUp) from the last Cell and Last Column in a row can be find using End(xlToLeft). For e.g. Range("A1048576").End(xlUp).Row gives last used row of Column A.

15. Difference between ActiveX and Form Controls.


Ans:

i) Forms controls can be used on worksheets and chart sheets. Forms controls can also be placed within embedded charts in Classic Excel (though not in Excel 2007). ActiveX controls can only be used on worksheets. ActiveX controls do not work in MacExcel.
ii) The Forms controls aren’t very complicated, and they have been part of Excel for longer (they were used in Excel 5/95’s dialog sheets) than the Controls Toolbox (Excel 97), so it stands to reason that they’d be more seamlessly integrated. Being newer, the ActiveX controls have richer formatting possibilities. Both can link to cells and ranges in the worksheet.

16. What is the difference b/w Functions and Subroutines?


Ans: There are so many differences. I noted few.
i) Subroutines never return a value but function does return values.
ii) A function could not change the values of actual arguments whereas a subroutine could change them.
iii) A subroutine cannot be used in a worksheet
iv) A subroutine can manipulate the any objects. A Function Cannot.
v) A function will not be listed in the names of macros

17. How to debug a VBA code?


Ans:
Using Breakpoints(F9), Step-by-step execution (F8), Debug.Print & Immediate Window and Watch window.

18. Draw basic Excel Object Model.


Ans:
Application --> Workbooks --> Worksheets --> Range / Chart

19. What are properties, methods, events and objects?


Ans:
For details click here --> http://msdn.microsoft.com/en-us/library/ms172576%28VS.80%29.aspx
All the controls in the ToolBox except the Pointer are objects in Visual Basic. These objects have associated properties, methods and events.
A property is a named attribute of a programming object. Properties define the characteristics of an object such as Size, Color etc. or sometimes the way in which it behaves.
A method is an action that can be performed on objects. For example, a cat is an object. Its properties might include long white hair, blue eyes, 3 pounds weight etc. A complete definition of cat must only encompass on its looks, but should also include a complete itemization of its activities. Therefore, a cat's methods might be move, jump, play, breath etc.
Visual Basic programs are built around events. Events are various things that can happen in a program. Let us consider a TextBox control and a few of its associated events to understand the concept of event driven programming. The TextBox control supports various events such as Change, Click, MouseMove and many more that will be listed in the Properties dropdown list in the code window for the TextBox control. We will look into a few of them as given below.
* The code entered in the Change event fires when there is a change in the contents of the TextBox
* The Click event fires when the TextBox control is clicked.
* The MouseMove event fires when the mouse is moved over the TextBox

20. Union is used for _____________ ?


Ans:
To unite the different ranges depending on the logic. It is similar to set union, here range works as set. For eg. Set nrange = Union(rng1,rng2)