Clojure，更新地图中的嵌套内容

Question

I am confused about the required syntax for updating a value in a map, where said value is a vector of maps.

Given a map:

   {:data-extracts [
                       {:name "some name"
                        :data "some data"
                        }]}

How can I update the value of :data, I know you can use assoc or conj to modify maps (well return new maps) but I'm unsure how this works when nested elements are present.

desired result:

   {:data-extracts [
                       {:name "some name"
                        :data "new data"
                        }]}

Is there a way to do something like the following?

(update :data-extracts :data "new data")

How is this achieveable?

I tried the following:

(assoc opts :data-extracts [:name "Secret Escapes"
                            :data "new data"]))

But that doesn't work as I expected.

Answer 1

When using nested structures, you'll want to use *-in -functions (in this case assoc-in ) and specify one key for each nesting level. In case of vectors, it's just index, in case of maps it's obvious:

(assoc-in [:data-extracts 0 :data] "new data")