How to improve the speed of VBA macro code?

Question

I do not have much experience with writing macros, and therefore need the help of this community for the following issue encountered:

My macro copies a range of valu

Answer 1

Best way to improve performance based on my experience is to work on variables in code rather than accessing the spreadsheet every time you want to lookup a value. Save any range you want to work with in a variable(variant) and then iterate through it as if it was the sheet.

    dim maxRows as double
    dim maxCols as integer.
    dim data as variant
with someSheet
    maxRows = .Cells(rows.count, 1).end(xlUp).row             'Max rows in sheet
    maxCols = .Cells(1, columns.count).end(xlToLeft).column   'max columns in sheet
    data = .Range(.Cells(1,1), .Cells(maxRows, maxCols))      'copy range in a variable
end with

From here you can access the data variable as if it was the spreadsheet like - data(row, column) with MUCH MUCH faster read speed.