Table Of Contents
Excel VBA Functions
We have seen that we can use the worksheet functions in VBA, i.e., the Excel worksheet functions in VBA coding using the Application.Worksheet method. But how do we use a function of VBA in Excel well? Such functions are called user-defined functions. When a user creates a function in VBA, we can use it in an Excel worksheet.
Although we have many functions in Excel to manipulate the data, sometimes we need to have some customization in the tools to save time as we do some tasks repeatedly. For example, we have predefined functions in excel like SUM, COUNTIF, SUMIF, COUNTIFS, VLOOKUP, INDEX, MATCH in excel, etc., but we do some tasks daily for which a single command or function is not available in Excel. Using VBA, we can create the User Defined Functions (UDF) custom function.
What do VBA Functions do?
- They carry out certain calculations; and
- Return a value
In VBA, while defining the function, we use the following syntax to specify the parameters and their data type.
Data type here is the type of data the variable will hold. It can hold any value (data type or class object).
We can connect the object with its property or method using the period or dot (.) symbol.
How to Create Custom Functions using VBA?
Example
Suppose we have the following data from a school where we need to find the total marks scored by the student, result, and grade.
To sum up, the marks scored by an individual student in all subjects, we have an inbuilt function, SUM. But, determining the grade and result based on the criteria set out by the school is not available in Excel by default.
It is the reason why we need to create user-defined functions.
Step 1: Find Total Marks
First, we will find the total marks using the SUM function in excel.
Then, press the "Enter" key to get the result.
Drag the formula to the rest of the cells.
Now, to find out the result (passed, failed, or essential repeat), the criteria set by the school is that.
- Suppose a student has scored more than or equal to 200 as total marks out of 500. In addition, suppose they have also not failed in any subject (scored more than 32 in each subject), a student is passed.
- If the student scored more than or equal to 200 but failed in 1 or 2 subjects, then a student will get āEssential Repeatā in those subjects.
- If the student has scored either less than 200 or fails in 3 or more subjects, then the student failed.
Step 2: Create ResultOfStudent Function
To create a function named āResultOfStudent,ā we need to open āVisual Basic Editorā by using any of the methods below:
- Using the Developer tab excel.
If the Developer tab is not available in MS Excel, then we can get that by using the following steps:
- Right-click anywhere on the ribbon. Then, choose to Customize the Ribbon in excel'.
When we choose this command, the āExcel Optionsā dialog box opens.
- We need to check the box for āDeveloperā to get the tab.
- Using the shortcut key, Alt+F11.
- When we open the VBA editor, we need to insert the module by going to the Insert menu and choosing a module.
- We need to paste the following code into the module.
Function ResultOfStudents(Marks As Range) As String Dim mycell As Range Dim Total As Integer Dim CountOfFailedSubject As Integer For Each mycell In Marks Total = Total + mycell.Value If mycell.Value < 33 Then CountOfFailedSubject = CountOfFailedSubject + 1 End If Next mycell If Total >= 200 And CountOfFailedSubject <= 2 And CountOfFailedSubject > 0 Then ResultOfStudents = "Essential Repeat" ElseIf Total >= 200 And CountOfFailedSubject = 0 Then ResultOfStudents = "Passed" Else ResultOfStudents = "Failed" End If End Function
The above function returns the result for a student.
We need to understand how this code is working.
The first statement, āFunction ResultOfStudents(Marks As Range) As String,ā declares a function named āResultOfStudentsā that will accept a range as input for marks and return the result as a string.
Dim mycell As Range Dim Total As Integer Dim CountOfFailedSubject As Integer
These three statements declare variables, i.e.,
- āmyCellā as a Range,
- āTotalā as Integer (to store total marks scored by a student),
- āāCountOfFailedSubjectā is an Integer (to store the number of subjects a student has failed).
For Each mycell In Marks Total = Total + mycell.Value If mycell.Value < 33 Then CountOfFailedSubject = CountOfFailedSubject + 1 End If Next mycell
This code checks for every cell in the āMarksā range. It adds the value of every cell in the āTotalā variable. If the cell's value is less than 33, add 1 to the āCountOfFailedSubjectā variable.
If Total >= 200 And CountOfFailedSubject <= 2 And CountOfFailedSubject > 0 Then ResultOfStudents = "Essential Repeat" ElseIf Total >= 200 And CountOfFailedSubject = 0 Then ResultOfStudents = "Passed" Else ResultOfStudents = "Failed" End If
This code checks the value of āTotalā and āCountOfFailedSubjectā and passes the āEssential Report,ā āPassed,ā or āFailedā to the āResultOfStudents.ā
Step 3: Apply ResultOfStudents Function to Get Result
ResultOfStudents function takes marks, i.e., selecting 5 marks scored by the student.
Now, select the range of cells, B2: F2.
Drag the formula to the rest of the cells.
Step 4: Create 'GradeForStudent' Function to get Grades
Now to find out the grade for the student, we will create one more function named āGradeForStudent.ā
The code would be:
Function GradeForStudent(TotalMarks As Integer, Result As String) As String If TotalMarks > 440 And TotalMarks <= 500 And ((Result = "Passed" Or Result = "Essential Repeat") Or Result = "Essential Repeat") Then GradeForStudent = "A" ElseIf TotalMarks > 380 And TotalMarks <= 440 And (Result = "Passed" Or Result = "Essential Repeat") Then GradeForStudent = "B" ElseIf TotalMarks > 320 And TotalMarks <= 380 And (Result = "Passed" Or Result = "Essential Repeat") Then GradeForStudent = "C" ElseIf TotalMarks > 260 And TotalMarks <= 320 And (Result = "Passed" Or Result = "Essential Repeat") Then GradeForStudent = "D" ElseIf TotalMarks >= 200 And TotalMarks <= 260 And (Result = "Passed" Or Result = "Essential Repeat") Then GradeForStudent = "E" ElseIf TotalMarks < 200 Or Result = "Failed" Then GradeForStudent = "F" End If End Function
This function assigns a āGradeā to the student based on the āTotal Marksā and āResult.ā
We need to write the formula and open the brackets in cell H2. Press Ctrl+Shift+A to find out the arguments.
The GradeForStudent function takes Total marks (sum of marks) and the result of the student as an argument to calculate the grade.
Now, select the individual cells, G2 and H2.
Now, we need to press Ctrl+D after selecting the cells to copy down the formulas.
We can highlight the values of less than 33 with the red background color to find out the subjects in which the student failed.