Adding thousand separator to item variable map_scale

Question

Using [%round(map_get(item_variables('MyMap'),'map_scale'))%] in a text field in the print composer we can retrieve scale of the targeted map item. The output of the expression is e.g. 10000 - but I would like to add a thousand separator, so the output looks like 10,000.

I am aware that I could check for length of returned string and add the separators by concatenation, but that is tedious to create, error-prone and needs an additional check for lengths above 6 digits, too.

So, using QGIS 3.10 is there an option to add the thousand separator to the returned value of the expression mentioned at the beginning?

---

Side note: Using the numeric scale bar is possible, but not desired, since I want to incorporate the variable into a small text item.

Answer 1

As suggested by @snaileater, you can use format_number like so:

 format_number( round(map_get(item_variables('myMap'),'map_scale')),0)

This will make your number a string and add commas as thousand separator, you can specify a language to determine what formatting will be used.