The science behind the With...End With structure is pretty simple:

1) The "." is used as shorthand for whatever follows the With, so


With Worksheets("Sheet1")
.Range("J2", .Range("J2").End(xlDown)).Copy
End With

is shorter, and perhaps faster to write than

Worksheets("Sheet1").Range("J2", _
Worksheets("Sheet1").Range("J2").End(xlDown)).Copy

2) In the second example, the Worksheets("Sheet1") reference has to
be resolved twice. Using With...End With, the worksheets("Sheet1")
reference is only resolved once. Resolving object (Workbook,
Worksheet, Range, etc.) references is very time and resource
consuming, so the With...End With structure is also more efficient
any time you have more than one reference to an object.


In article ,
"Joe 90" wrote:

Your extra "dots" worked a treat, and this will help me enormously with my
coding. just wish I properly understood the science behind it, although I
see what you say about the second range not being qualified.