Do While Loop in VBA

A Do While loop repeats VBA statements while a specified condition is True.

Basic structure:

Do While condition

    statements

Loop

The condition is checked before each iteration.

Do While is useful when you want code to continue running as long as a condition is satisfied.

Common uses include:

• Processing records until a condition changes.
• Reading data while cells contain values.
• Repeating calculations.
• Processing student records.
• Searching through worksheet data.
• Repeating a task until a limit is reached.

The basic syntax is:

Do While condition

    statements

Loop

VBA checks the condition. If it is True, the statements execute. The condition is checked again when VBA reaches Loop.

The following example displays numbers from 1 to 5.

Dim i As Integer

i = 1

Do While i <= 5

    MsgBox i

    i = i + 1

Loop

The loop continues while i <= 5.

The condition determines whether the loop should continue.

Do While i <= 5

When the condition is True, the loop executes. When it becomes False, the loop stops.

Before starting a Do While loop, the variable used in the condition should normally have an appropriate initial value.

Dim i As Integer

i = 1

Do While i <= 5
    MsgBox i
    i = i + 1
Loop

Here, i starts with the value 1.

The loop variable must usually be changed inside the loop so that the condition can eventually become False.

i = i + 1

Without updating the variable in an appropriate way, the loop may continue indefinitely.

A Do While loop can write values into Excel cells.

Dim i As Integer

i = 1

Do While i <= 5

    Cells(i, 1).Value = i

    i = i + 1

Loop

This writes numbers 1 to 5 into cells A1 through A5.

You can repeatedly write text into cells.

Dim i As Integer

i = 1

Do While i <= 5

    Cells(i, 1).Value = "Student"

    i = i + 1

Loop

The word Student is written into five cells.

The loop can perform a calculation during every iteration.

Dim i As Integer

i = 1

Do While i <= 10

    Cells(i, 1).Value = i * 10

    i = i + 1

Loop

This writes 10, 20, 30, and so on up to 100.

An If statement can be placed inside a Do While loop.

Dim i As Integer

i = 2

Do While i <= 10

    If Cells(i, 2).Value >= 40 Then
        Cells(i, 3).Value = "Pass"
    Else
        Cells(i, 3).Value = "Fail"
    End If

    i = i + 1

Loop

This checks student marks row by row.

MsgBox can be used inside a Do While loop.

Dim i As Integer

i = 1

Do While i <= 3

    MsgBox "Hello " & i

    i = i + 1

Loop

Three message boxes will be displayed.

A counter is often used to control the loop.

Dim count As Integer

count = 1

Do While count <= 10

    MsgBox count

    count = count + 1

Loop

The counter increases by one during each iteration.

You can process a worksheet range using a row counter.

Dim rowNumber As Integer

rowNumber = 2

Do While rowNumber <= 10

    Cells(rowNumber, 1).Font.Bold = True

    rowNumber = rowNumber + 1

Loop

Rows 2 through 10 are processed.

Do While can process student records one row at a time.

Dim rowNumber As Integer

rowNumber = 2

Do While rowNumber <= 11

    Cells(rowNumber, 4).Value = "Active"

    rowNumber = rowNumber + 1

Loop

The status of rows 2 through 11 is set to Active.

A Do While loop can continue while a cell contains data.

Dim rowNumber As Integer

rowNumber = 2

Do While Cells(rowNumber, 1).Value <> ""

    MsgBox Cells(rowNumber, 1).Value

    rowNumber = rowNumber + 1

Loop

The loop continues while column A contains a value.

A Do While loop can be used to search through worksheet data.

Dim rowNumber As Integer

rowNumber = 2

Do While Cells(rowNumber, 1).Value <> ""

    If Cells(rowNumber, 1).Value = "Rahul" Then
        MsgBox "Rahul Found"
    End If

    rowNumber = rowNumber + 1

Loop

A loop can calculate the total of values stored in a worksheet.

Dim rowNumber As Integer
Dim total As Double

rowNumber = 2
total = 0

Do While rowNumber <= 6

    total = total + Cells(rowNumber, 2).Value

    rowNumber = rowNumber + 1

Loop

MsgBox "Total = " & total

A Do While loop can contain several statements.

Dim i As Integer

i = 1

Do While i <= 5

    Cells(i, 1).Value = i
    Cells(i, 2).Value = i * 10
    Cells(i, 3).Value = i * 100

    i = i + 1

Loop

Each iteration performs three operations.

You can create a multiplication table using a Do While loop.

Dim i As Integer
Dim number As Integer

number = 5
i = 1

Do While i <= 10

    Cells(i, 1).Value = number & " x " & i
    Cells(i, 2).Value = number * i

    i = i + 1

Loop

InputBox can be used inside a loop, although the loop must have a clear stopping condition.

Dim number As Integer
Dim count As Integer

count = 1

Do While count <= 3

    number = CInt(InputBox("Enter a number:"))

    MsgBox "You entered " & number

    count = count + 1

Loop

The user is asked for a number three times.

A Boolean variable can control a Do While loop.

Dim continueLoop As Boolean
Dim i As Integer

continueLoop = True
i = 1

Do While continueLoop

    MsgBox i

    i = i + 1

    If i > 3 Then
        continueLoop = False
    End If

Loop

The loop stops when the Boolean variable becomes False.

Different comparison operators can be used in the condition.

Dim i As Integer

i = 10

Do While i > 0

    MsgBox i

    i = i - 1

Loop

The loop continues while i > 0.

Do While is particularly useful when processing a list until an empty cell is encountered.

Dim rowNumber As Integer

rowNumber = 2

Do While Cells(rowNumber, 1).Value <> ""

    Cells(rowNumber, 2).Value = "Processed"

    rowNumber = rowNumber + 1

Loop

The loop continues until an empty cell is found in column A.

The following example checks student marks until an empty student name is found.

Dim rowNumber As Integer

rowNumber = 2

Do While Cells(rowNumber, 1).Value <> ""

    If Cells(rowNumber, 2).Value >= 40 Then

        Cells(rowNumber, 3).Value = "Pass"

    Else

        Cells(rowNumber, 3).Value = "Fail"

    End If

    rowNumber = rowNumber + 1

Loop

Column A contains student names, column B contains marks, and column C receives the result.

Beginners commonly make these mistakes:

• Forgetting to initialize the loop variable.
• Forgetting to update the variable.
• Creating a condition that never becomes False.
• Using the wrong cell or row reference.
• Forgetting the Loop statement.
• Processing more rows than intended.

A loop that never makes its condition False can continue indefinitely.

The following example processes records until an empty cell is found.

Dim rowNumber As Integer

rowNumber = 2

Do While Cells(rowNumber, 1).Value <> ""

    Cells(rowNumber, 4).Value = "Processed"
    rowNumber = rowNumber + 1

Loop

MsgBox "Processing Completed"

This is useful for simple Excel data-processing tasks.

• Always make the loop condition clear.
• Initialize variables before starting the loop.
• Make sure the condition can eventually become False.
• Update the controlling variable when required.
• Test the loop with a small amount of data first.
• Use meaningful variable names.
• Be careful when processing large worksheets.

A typical Do While workflow is:

1. Declare the controlling variable.
2. Give it an initial value.
3. Write the Do While condition.
4. Execute the required statements.
5. Update the controlling variable.
6. Reach the Loop statement.
7. Check the condition again.
8. Stop when the condition becomes False.

Dim i As Integer

i = 1

Do While i <= 5

    Cells(i, 1).Value = i

    i = i + 1

Loop

The Do While loop is an important VBA looping structure that repeats code while a specified condition remains True.

It is particularly useful when processing Excel data until a condition changes, such as processing rows until an empty cell is found.

Dim rowNumber As Integer

rowNumber = 2

Do While Cells(rowNumber, 1).Value <> ""

    If Cells(rowNumber, 2).Value >= 40 Then

        Cells(rowNumber, 3).Value = "Pass"

    Else

        Cells(rowNumber, 3).Value = "Fail"

    End If

    rowNumber = rowNumber + 1

Loop

In this example, VBA continues processing student records while column A contains a student name. The marks are checked and the result is written into column C.

The next lesson will introduce the Do Until loop, which repeats code until a specified condition becomes True.