Need explanation of how MAX() function works with Text Column

[Barkop_1]

Hello,

I have found  multiple dax masures where MAX() is used with Text column, but none of the found solution explained how exactly does it work.

For example I was looking for measure that would return name of the month that had the highest sales value during respective year.

I implemented this measure into my .pbix (fount this on community): 

Best month = calculate(Max('Date'[MonthName]) ,TOPN(1,all('Date'[MonthName]),calculate([SalesUnits] )), values('Date'[MonthName]))

and it works as intended. Screenshots below.

Could someone explain how does the MAX() work with Text Columns?

[HotChilli · Accepted solution]

MAX on a text value uses alphabetical order to return a scalar value.

In the measure shown, it's not "really" doing anything, TOPN is returning a table with 1 value -  just preventing a syntax error due to measures requiring an aggregation. 

If there were 2 months with the same SalesUnits, it would give you the later month in the alphabet eg, sep ahead of feb