The documentation (https://docs.qgis.org/3.4/en/docs/user_manual/working_with_vector/expression.html#id31) says:

To use these functions in an expression, they should be preceded by @ character (e.g, @row_number).

map_scale is one of these variables. But if you see the example map_get( item_variables('Map 0'), 'map_scale')it is used without an @

Why is it in this case used without an @?

  • 1
    in this case it is necessary to read the syntax of the map_get function (map_get (map, key)): in this case map_scale represents the key – pigreco Apr 13 at 11:47
  • @pigreco, it's a little bit confusing. Is there some documentation that describes the difference, when using it with or without? – PieterB Apr 13 at 11:53
  • to my knowledge there is no detailed documentation on these topics – pigreco Apr 13 at 15:04

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