Saying we have an association:
asc = <|"A" -> <|"a" -> 1, "b" -> 2, "c" -> 3|>|>; I want to updated values of "A". I have tried doing:
AssociateTo[ asc, asc["A"][#] -> If[asc["A"][#] === 1, 0 , asc["A"][#]] & /@ {"a", "b", "c"}]
<|"A" -> <|"a" -> 1, "b" -> 2, "c" -> 3|>, 1 -> 0, 2 -> 2, 3 -> 3|>
But this just adds valuesst to the association instead of adding to "A"
How can I update the values in "A" using AssociateTo?
One possibility would be the simple
asc["A"]["a"] = 99;
As @m_goldberg commented this can be shortened to
asc["A", "a"] = 99; To change several keys:
asc[[1]][[2 ;; 3]] = 4 
asc["A", "a"] = 99; $\endgroup$ I have came up with a solution:
In[1]:= asc = <|"A" -> <|"a" -> 1, "b" -> 2, "c" -> 3|>|>; Module[{tmp = asc["A"]}, AssociateTo[tmp, # -> tmp[#] + 1 & /@ {"a"}]; AssociateTo[asc, "A" -> tmp] ] Out[2]= <|"A" -> <|"a" -> 2, "b" -> 2, "c" -> 3|>|> AssocTo? It is a very poor tool for solving your problem. The simple expression asc["A", "a"] = asc["A", "a"] + 1; is much better. $\endgroup$