4 Examples top

• link | changes

  ;; create hash map the long way
  user=> (hash-map)
  {}
  
  ;; create hash map the short way
  user=> {}
  {}
  
  ;; sending a key more times, will remap it to the last value
  user=> (hash-map :key1 1, :key1 2) 
  {:key1 2} 
  
  user=> {:key1 1, :key1 2}
  IllegalArgumentException Duplicate key: :key1  clojure.lang.PersistentArrayMap.createWithCheck (PersistentArrayMap.java:70)
  
  
  user=> (hash-map :key1 'val1, 'key2 :val2, [:compound :key] nil)
  {[:compound :key] nil, :key1 val1, key2 :val2} 
  
  

  ;; create hash map the long way user=> (hash-map) {} ;; create hash map the short way user=> {} {} ;; sending a key more times, will remap it to the last value user=> (hash-map :key1 1, :key1 2) {:key1 2} user=> {:key1 1, :key1 2} IllegalArgumentException Duplicate key: :key1 clojure.lang.PersistentArrayMap.createWithCheck (PersistentArrayMap.java:70) user=> (hash-map :key1 'val1, 'key2 :val2, [:compound :key] nil) {[:compound :key] nil, :key1 val1, key2 :val2}
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  user=> (map #(hash-map % 0) (seq "abcdefgh"))
  ({\a 0} {\b 0} {\c 0} {\d 0} {\e 0} {\f 0} {\g 0} {\h 0}) 
  
  user=> (apply hash-map (.split "a 1 b 2 c 3" " "))
  {"a" "1", "b" "2", "c" "3"}

  user=> (map #(hash-map % 0) (seq "abcdefgh")) ({\a 0} {\b 0} {\c 0} {\d 0} {\e 0} {\f 0} {\g 0} {\h 0}) user=> (apply hash-map (.split "a 1 b 2 c 3" " ")) {"a" "1", "b" "2", "c" "3"}
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  ;;another way of creating hash map is by using def
  user=> (def user {:name "Steve" :age 24 :salary 7886 :company "Acme"})
  {:age 24, :name "Steve", :salary 7756, :company "Acme"}
  
  
  

  ;;another way of creating hash map is by using def user=> (def user {:name "Steve" :age 24 :salary 7886 :company "Acme"}) {:age 24, :name "Steve", :salary 7756, :company "Acme"}
• link | changes

  ; Take a sequence of sequences (vector of vectors, and create a map
  ; using date as the map key.
  (def csv1 [["01/01/2012" 1 2 3 4]["06/15/2012" 38 24 101]])
  
  (map #(hash-map (keyword (first %1)) (vec (rest %1))) csv1)
  ({:01/01/2012 [1 2 3 4]} {:06/15/2012 [38 24 101]})
  

  ; Take a sequence of sequences (vector of vectors, and create a map ; using date as the map key. (def csv1 [["01/01/2012" 1 2 3 4]["06/15/2012" 38 24 101]]) (map #(hash-map (keyword (first %1)) (vec (rest %1))) csv1) ({:01/01/2012 [1 2 3 4]} {:06/15/2012 [38 24 101]})