Category Archives: JS-API

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. The JS can correctly read these large numbers – it just silently gets the wrong … 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

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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

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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 , , , , | 5 Comments