How to use the ISNULL/empty Function (VBA) - excel

Question

Trying something like this. My code is find the value of cell B7 of Sheet1 in column A of Sheet15. If it is not found, do nothing. If it is found, write the value in the cell next to the found value to the next available cell in column F of Sheet4.
I have this number in Sheet1
Code will find that Sheet1 value in Sheet2 Col"A" then copy the Col"B" value that is "156".
After that code will paste that "156" VALUE IN Sheet3.Range("C2") to till where Col"B" used range end.
Looking forward to your help.
Dim lastR4 As Long
lastR4 = Sheet4.Range("E" & Rows.Count).End(xlUp).Row
If Sheet15.Range("A2:B2") Is Empty Then
Exit Sub
Else
Sheet4.Range("F11:F" & lastR4).Value = Sheet15.Range("A" & _
WorksheetFunction.Match(Sheet1.Range("B7").Value, Sheet15.Range("A:A"), 0)).Offset(0, 1)
End If

Answer 1

Try the next slightly adapted code, please:
Sub testFillDat()
Dim lastR4 As Long
lastR4 = Sheet4.Range("E" & rows.count).End(xlUp).row
If WorksheetFunction.CountA(Sheet15.Range("A2:B2")) = 0 Then
Exit Sub
Else
If Sheet15.Range("B2") = "" Then
Sheet4.Range("F11:F" & lastR4).Value = 0
Else
Sheet4.Range("F11:F" & lastR4).Value = Sheet15.Range("A" & _
WorksheetFunction.match(Sheet1.Range("B7").Value, Sheet15.Range("A:A"), 0)).Offset(0, 1)
End If
End If
End Sub
If there is no match of "B7" (Sheet1) in "A:A" (Sheet15) the code will raise an error. It can be adapted to catch it, but I only tried to show you how checking if a range with multiple cells is empty... In rest, your code should work.

Answer 2

Lookup Using Application.Match
Using Application.Match is easier and cleaner then using WorksheetFunction.Match because you can test the result with IsError or IsNumeric.
The Code
Option Explicit
Sub test()
' The cell containing the lookup value.
Dim cel1 As Range
Set cel1 = Sheet1.Range("B7")
' First 'available' cell in column `E` column, but in column `F`.
Dim cel4 As Range
Set cel4 = Sheet4.Range("E" & Sheet4.Rows.Count).End(xlUp).Offset(1, 1)
' Range from cell `A1` to the last non-empty cell.
Dim rng15 As Range
Set rng15 = Sheet15.Range("A1", Sheet15.Range("A" & Sheet15.Rows.Count).End(xlUp))
' The index of the found value. If not found, returns error value.
' Therefore we use 'Variant'.
Dim cMatch As Variant
cMatch = Application.Match(cel1.Value, rng15, 0)
' Test if found with 'IsNumeric()'. You can also use 'Not IsError()'
' instead. Or even 'IsError()', but then switch the statements.
If IsNumeric(cMatch) Then
cel4.Value = rng15.Cells(cMatch).Offset(, 1).Value
MsgBox "Value '" & cel1.Value & "' copied.", vbInformation, "Success"
Else
MsgBox "Value '" & cel1.Value & "' not found.", vbCritical, "Fail"
End If
End Sub
EDIT
Adjust the sheets and cells appropriately.
Fill Range with Found Value
Sub test2()
' The cell containing the lookup value.
Dim cel1 As Range
Set cel1 = Sheet1.Range("B7")
' Range from cell 'E2' to the last non-empty cell, but column `F`.
Dim rng4 As Range
Set rng4 = Sheet4.Range("E2", Sheet4.Range("E" & Sheet4.Rows.Count) _
.End(xlUp)).Offset(, 1)
' Range from cell `A1` to the last non-empty cell.
Dim rng15 As Range
Set rng15 = Sheet15.Range("A1", Sheet15.Range("A" & Sheet15.Rows.Count) _
.End(xlUp))
' The index of the found value. If not found, returns error value.
' Therefore we use 'Variant'.
Dim cMatch As Variant
cMatch = Application.Match(cel1.Value, rng15, 0)
' Test if found with 'IsNumeric()'. You can also use 'Not IsError()'
' instead. Or even 'IsError()', but then switch the statements.
If IsNumeric(cMatch) Then
rng4.Value = rng15.Cells(cMatch).Offset(, 1).Value
MsgBox "Value '" & cel1.Value & "' copied.", vbInformation, "Success"
Else
MsgBox "Value '" & cel1.Value & "' not found.", vbCritical, "Fail"
End If
End Sub