In clojure, how can I select and return a subset of a collection












0















If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure







share|improve this question























  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35
















0















If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure







share|improve this question























  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35














0












0








0








If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure







share|improve this question














If I have a collection like this



{{:A "a" :B "b"} {:A "a" :B "Goal" } {:A "a" :B "Goal"}}


how do I make a function so it returns only the parts where :B "Goal"? Meaning only:



{{:A "a" :B "Goal" } {:A "a" :B "Goal"}}





collections clojure




collections clojure






share|improve this question













share|improve this question











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asked Nov 20 '18 at 23:36









John SlaineJohn Slaine

799




799













  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35



















  • curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

    – manandearth
    Nov 21 '18 at 17:35

















curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

– manandearth
Nov 21 '18 at 17:35





curly brackets are maps in Clojure and require an even number of members (key and value pairs) they can be of any type : keyword, string, number.. your collection above will be better represented as a vector [,,,] or a list'(,,,)

– manandearth
Nov 21 '18 at 17:35












1 Answer
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I fixed your data to make it a vector of 3 maps.



(def data [{:A "a" :B "b"}

           {:A "a" :B "Goal"}

           {:A "a" :B "Goal"}])



(defn b-goal?

  [item]

  (= (:B item) "Goal") )



(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



Be sure also to check out:




  • The Clojure CheatSheet

  • Clojure for the Brave and True


As well as books like




  • Living Clojure

  • Getting Clojure






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    1 Answer
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    1 Answer
    1






    active

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    active

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    active

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    6














    I fixed your data to make it a vector of 3 maps.



    (def data [{:A "a" :B "b"}
    
           {:A "a" :B "Goal"}
    
           {:A "a" :B "Goal"}])
    

    
(defn b-goal?
    
  [item]
    
  (= (:B item) "Goal") )
    

    
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



    Be sure also to check out:




    • The Clojure CheatSheet

    • Clojure for the Brave and True


    As well as books like




    • Living Clojure

    • Getting Clojure






    share|improve this answer






























      6














      I fixed your data to make it a vector of 3 maps.



      (def data [{:A "a" :B "b"}
      
           {:A "a" :B "Goal"}
      
           {:A "a" :B "Goal"}])
      

      
(defn b-goal?
      
  [item]
      
  (= (:B item) "Goal") )
      

      
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



      Be sure also to check out:




      • The Clojure CheatSheet

      • Clojure for the Brave and True


      As well as books like




      • Living Clojure

      • Getting Clojure






      share|improve this answer




























        6












        6








        6







        I fixed your data to make it a vector of 3 maps.



        (def data [{:A "a" :B "b"}
        
           {:A "a" :B "Goal"}
        
           {:A "a" :B "Goal"}])
        

        
(defn b-goal?
        
  [item]
        
  (= (:B item) "Goal") )
        

        
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



        Be sure also to check out:




        • The Clojure CheatSheet

        • Clojure for the Brave and True


        As well as books like




        • Living Clojure

        • Getting Clojure






        share|improve this answer















        I fixed your data to make it a vector of 3 maps.



        (def data [{:A "a" :B "b"}
        
           {:A "a" :B "Goal"}
        
           {:A "a" :B "Goal"}])
        

        
(defn b-goal?
        
  [item]
        
  (= (:B item) "Goal") )
        

        
(filter b-goal? data) => ({:A "a", :B "Goal"} {:A "a", :B "Goal"})



        Be sure also to check out:




        • The Clojure CheatSheet

        • Clojure for the Brave and True


        As well as books like




        • Living Clojure

        • Getting Clojure







        share|improve this answer














        share|improve this answer



        share|improve this answer








        edited Nov 21 '18 at 1:43

























        answered Nov 20 '18 at 23:49









        Alan ThompsonAlan Thompson

        14k22533




        14k22533
































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