How does 'Drag to flash fill' works in MS EXCEL?

 The first two columns have the 'first' and 'last' names in them. Now I want to flash fill column C. I am not going to use a function or another way of concatenating the 'first' and 'last' names to come up with the last name in column C.

The icon shown in the next image will be useful for flash filling.

Now type a pattern such as 'Jay Krish' in the first row of Column C. Note this is just a pattern. 

Now place your cursor in column C's first row and click the icon shown previously.

The rest of the rows follow the pattern of the first row. You also see the flash fill icon on your data row.

How does dragging to fill rows of a column work in MS Excel work?

 Microsoft Excel is built for productivity and dragging the mouse on an Excel sheet is one such trick that increases the productivity.

It is better that I explain with examples.

In this example, you just place a number in a cell.

Drag down as suggested.

Well, this is not interesting. It just COPIED the starting cell.  This is because, the default drag-down operation is COPY.

In the above if you choose the option Fill Series, it will fill the consecutive numbers starting from 1.

Another example here. I just entered the first date as 1/1/2021 and dragged down and this is what I get.

Here is another example.

Well, here is an example. In the first column I have the first name of a client, in the second I have the last name. In the third column, I use the CONCAT () function to fill the first name. I just have to do this for the first row. 

After evaluating the function, I just DRAGGGGGGGGGGGGGGG! Voila, it fills the rest.

Instead of CONCAT (), the following also works.

Click here to see how 'flash fill' works.

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