Why I am not to update String as value in Dictionary if Dictionary is created with Int64 values

General Usage
2

When you initialize your dict like the above, the Dict created becomes specific for string keys and int values:

julia> d = Dict("a"=>1, "b" => 2, "c" => 3)
Dict{String, Int64} with 3 entries:
  "c" => 3
  "b" => 2
  "a" => 1

(note the Dict{String, Int64}).

If you want the Dict to contain more general values than those used to initialize the dict, you can be explicit about that, for example:

julia> d = Dict{String,Union{String,Int}}("a"=>1, "b" => 2, "c" => 3)
Dict{String, Union{Int64, String}} with 3 entries:
  "c" => 3
  "b" => 2
  "a" => 1

julia> d["c"] = "a"
"a"

julia> d
Dict{String, Union{Int64, String}} with 3 entries:
  "c" => "a"
  "b" => 2
  "a" => 1

or, even more general:

julia> d = Dict{String,Any}("a"=>1, "b" => 2, "c" => 3)
Dict{String, Any} with 3 entries:
  "c" => 3
  "b" => 2
  "a" => 1

julia> d["c"] = [1,2,3]
3-element Vector{Int64}:
 1
 2
 3

julia> d
Dict{String, Any} with 3 entries:
  "c" => [1, 2, 3]
  "b" => 2
  "a" => 1
6 Likes