Reading values from a Vector Sequentially

We can read values in a vector sequentially, eg. one after the other, using the functions first, second, last and rest.

Get specific values from a vector

Use the first, second, last and rest functions to read values from a vector, for example [1 2 "three" [4 5] :emoji-smile]

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You can also combine these functions, so the results of one function call can be used by another function call.

How do we get just the third value in a vector?

Using any of the functions first, second, rest, how to we get the third value from the vector ["Birthdays are" "full of" "presents" "that you" "always dreamd" "of having"]

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Reveal answer...

We want the returned answer to be "presents" and there are several ways we could do this

We can call one function and use its return value as an argument to another function.

;; rest function returns all values but the first one.
;; the second value can then be returned from the collection
(second
  (rest
    ["Birthdays are" "full of" "presents" "that you" "always dreamd" "of having"]))

We can also use a local name to hold some of the values in the collection and then use that name to get the right answer.

;; the let function assignes a name to our collection of values
;; then we get the value in third place by using the name.
(let [my-values ["Birthdays are" "full of" "presents"
              "that you" "always dreamd" "of having"]]
      (second (rest my-values)))

Hint

These functions also work with a list too.

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