Author Archives: fastexcel

Excel 2016 Performance Improvements

Excel 2016 Performance Improvements The Excel team has made a number of performance improvements to Excel 2016. These improvements were rolled out as part of the Office update cycle. The timescale that updates become available to you depends on which … Continue reading

Posted in Uncategorized | 6 Comments

Strategies for getting the last row in Excel with VBA

Using VBA to get the last row in Excel can be a surprisingly complex task. This post will explore some of the different strategies you can use. The first thing to do is to decide what you mean by “The … Continue reading

Posted in Excel, Formatting, VBA | Tagged , | 9 Comments

Excel JavaScript API Part 5: The large numbers bug

There is currently (JavaScript Excel API set 1.4) a rather nasty bug when writing large integer numbers (anything larger than int32) back to a range. 30 January 2018 – API set 1.7 – this bug is still there! The JS … Continue reading

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Excel JavaScript API Part 4: The shallow copy problem

I was trying to read the values from a Range and then write modified versions of the values to two different ranges. Should be straightforward: Well this does not work: both B4 and B6 have 0.91 added to them: wrong … Continue reading

Posted in arrays, Excel, JS-API | Tagged , | 1 Comment

Excel JavaScript API Part 3: Benchmark of Processing Arrays Performance – Loop vs Reduce vs COUNTIFS vs VBA

In a previous post I compared several different ways of processing data with VBA. The fastest way was to get the data into a variant array and loop on it. JavaScript has some powerful array methods so I wanted to … Continue reading

Posted in arrays, JS-API, VBA | Tagged , , | 4 Comments

Excel JavaScript API Part 2: Benchmark of Read/Write Range Performance

As an Excel Office Developer many of the Excel based applications I develop depend on reading data from Excel worksheet ranges, processing it and then writing the processed data back to a worksheet. In VBA the way to do this … Continue reading

Posted in arrays, Calculation, JS-API, VBA | Tagged , , | 1 Comment

Excel Range.Value(ValueType): What is this parameter?

Whilst visiting Microsoft Research in Cambridge I was chatting to fellow MVP Roger Govier. He mentioned that he was using this strange parameter to the Range.Value (ValueType) method, which I had been meaning to look at for a long time … Continue reading

Posted in Formatting, VBA | Tagged , | 7 Comments

Excel JavaScript API Part 1: Overview & Comparison

I have been spending time in the last few months experimenting with the new JavaScript Excel API. This is the first of a planned series of posts examining the JS-API from the point of view of an Excel Office developer. … Continue reading

Posted in .NET, JS-API, UDF, Uncategorized, VBA, XLL | Tagged , , , , | 7 Comments

Why Structured References are slow in Excel 2013 but fast in Excel 2016

Tables have a bad reputation for performance. Zack (Firefytr) Barresse (who wrote the definitive guide to Excel Tables with Kevin (Zorvek) Jones) recommends a limit of around 10K rows for tables if you want to keep performance reasonable. Prompted by … Continue reading

Posted in Calculation | Tagged , , , , , | 5 Comments

Excel Versions Screen Test (Updated): how fast is Screen Updating?

Gurs has an interesting benchmark he has been running on various systems and Excel versions over the years. His results seem to show a massive performance decline in later Excel versions. Looking at his benchmark and its VBA code you … Continue reading

Posted in Calculation, Formatting, Uncategorized, VBA | 9 Comments