Formatting a 2d int array into a string using streams












3















I have the following array:



private static final int BOARD = {

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 }

};


And I want to create a String representation on it, so if I were to print it on the console, it should look like this:



[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]


I can get this done with 2 nested for loops, but I am trying to accomplish this using streams. This is what I got so far:



public String toString() {

    StringJoiner board = new StringJoiner("n");



    for (int i = 0; i < BOARD.length; i++) {

        board.add(

            IntStream.of(BOARD[i])

                .mapToObj(String::valueOf)

                .collect(Collectors.joining(",", "[", "]"))

        );

    }

    return board.toString();

}


Is this something possible? I'm not particularly interested in performance (feel free to add some comments on that regard if you want), I am just trying to do this in a single chain of stream operations.






java java-stream tostring collect







share|improve this question

























  • Arrays.stream(BOARD).map(Arrays::toString).map(row -> row.replace(" ", "")).collect(Collectors.joining("n"))

    – shmosel
    Nov 14 '18 at 3:39
















3















I have the following array:



private static final int BOARD = {

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 }

};


And I want to create a String representation on it, so if I were to print it on the console, it should look like this:



[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]


I can get this done with 2 nested for loops, but I am trying to accomplish this using streams. This is what I got so far:



public String toString() {

    StringJoiner board = new StringJoiner("n");



    for (int i = 0; i < BOARD.length; i++) {

        board.add(

            IntStream.of(BOARD[i])

                .mapToObj(String::valueOf)

                .collect(Collectors.joining(",", "[", "]"))

        );

    }

    return board.toString();

}


Is this something possible? I'm not particularly interested in performance (feel free to add some comments on that regard if you want), I am just trying to do this in a single chain of stream operations.






java java-stream tostring collect







share|improve this question

























  • Arrays.stream(BOARD).map(Arrays::toString).map(row -> row.replace(" ", "")).collect(Collectors.joining("n"))

    – shmosel
    Nov 14 '18 at 3:39














3












3








3








I have the following array:



private static final int BOARD = {

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 }

};


And I want to create a String representation on it, so if I were to print it on the console, it should look like this:



[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]


I can get this done with 2 nested for loops, but I am trying to accomplish this using streams. This is what I got so far:



public String toString() {

    StringJoiner board = new StringJoiner("n");



    for (int i = 0; i < BOARD.length; i++) {

        board.add(

            IntStream.of(BOARD[i])

                .mapToObj(String::valueOf)

                .collect(Collectors.joining(",", "[", "]"))

        );

    }

    return board.toString();

}


Is this something possible? I'm not particularly interested in performance (feel free to add some comments on that regard if you want), I am just trying to do this in a single chain of stream operations.






java java-stream tostring collect







share|improve this question
















I have the following array:



private static final int BOARD = {

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 },

    { 0, 0, 0, 0, 0 }

};


And I want to create a String representation on it, so if I were to print it on the console, it should look like this:



[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]


I can get this done with 2 nested for loops, but I am trying to accomplish this using streams. This is what I got so far:



public String toString() {

    StringJoiner board = new StringJoiner("n");



    for (int i = 0; i < BOARD.length; i++) {

        board.add(

            IntStream.of(BOARD[i])

                .mapToObj(String::valueOf)

                .collect(Collectors.joining(",", "[", "]"))

        );

    }

    return board.toString();

}


Is this something possible? I'm not particularly interested in performance (feel free to add some comments on that regard if you want), I am just trying to do this in a single chain of stream operations.






java java-stream tostring collect




java java-stream tostring collect






share|improve this question















share|improve this question













share|improve this question




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edited Nov 14 '18 at 3:33









shmosel

36k43891




36k43891










asked Nov 14 '18 at 3:30









alejoalejo

19219




19219













  • Arrays.stream(BOARD).map(Arrays::toString).map(row -> row.replace(" ", "")).collect(Collectors.joining("n"))

    – shmosel
    Nov 14 '18 at 3:39



















  • Arrays.stream(BOARD).map(Arrays::toString).map(row -> row.replace(" ", "")).collect(Collectors.joining("n"))

    – shmosel
    Nov 14 '18 at 3:39

















Arrays.stream(BOARD).map(Arrays::toString).map(row -> row.replace(" ", "")).collect(Collectors.joining("n"))

– shmosel
Nov 14 '18 at 3:39





Arrays.stream(BOARD).map(Arrays::toString).map(row -> row.replace(" ", "")).collect(Collectors.joining("n"))

– shmosel
Nov 14 '18 at 3:39












3 Answers
3






active

oldest

votes


















1














You can nest the stream and map each level together, first by commas and then by the system line separator. Like,



return Arrays.stream(BOARD).map(a -> Arrays.stream(a)

            .mapToObj(String::valueOf).collect(Collectors.joining(",", "[", "]")))

            .collect(Collectors.joining(System.lineSeparator()));


I get



[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]

[0,0,0,0,0]





share|improve this answer































    4














    You can alternatively do it using Arrays.streamas :



    Arrays.stream(BOARD)
    
        .map(aBOARD -> IntStream.of(aBOARD)
    
                .mapToObj(String::valueOf)
    
                .collect(Collectors.joining(",", "[", "]")))
    
        .forEach(board::add);





    share|improve this answer

































      0














      Collections' toString() already provides that notation in the AbstractCollection class. Just use:-



      Arrays.stream(BOARD)
      
        .forEach(ints -> System.out.println(
      
                Arrays.stream(ints).boxed().collect(Collectors.toList()))
      
        );


      Or if you are happy to change int to Integer, you can even do:-



      Arrays.stream(BOARD)
      
        .forEach(ints -> System.out.println(Arrays.deepToString(ints)));





      share|improve this answer

























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        3 Answers
        3






        active

        oldest

        votes








        3 Answers
        3






        active

        oldest

        votes









        active

        oldest

        votes






        active

        oldest

        votes









        1














        You can nest the stream and map each level together, first by commas and then by the system line separator. Like,



        return Arrays.stream(BOARD).map(a -> Arrays.stream(a)
        
            .mapToObj(String::valueOf).collect(Collectors.joining(",", "[", "]")))
        
            .collect(Collectors.joining(System.lineSeparator()));


        I get



        [0,0,0,0,0]
        
[0,0,0,0,0]
        
[0,0,0,0,0]
        
[0,0,0,0,0]
        
[0,0,0,0,0]





        share|improve this answer




























          1














          You can nest the stream and map each level together, first by commas and then by the system line separator. Like,



          return Arrays.stream(BOARD).map(a -> Arrays.stream(a)
          
            .mapToObj(String::valueOf).collect(Collectors.joining(",", "[", "]")))
          
            .collect(Collectors.joining(System.lineSeparator()));


          I get



          [0,0,0,0,0]
          
[0,0,0,0,0]
          
[0,0,0,0,0]
          
[0,0,0,0,0]
          
[0,0,0,0,0]





          share|improve this answer


























            1












            1








            1







            You can nest the stream and map each level together, first by commas and then by the system line separator. Like,



            return Arrays.stream(BOARD).map(a -> Arrays.stream(a)
            
            .mapToObj(String::valueOf).collect(Collectors.joining(",", "[", "]")))
            
            .collect(Collectors.joining(System.lineSeparator()));


            I get



            [0,0,0,0,0]
            
[0,0,0,0,0]
            
[0,0,0,0,0]
            
[0,0,0,0,0]
            
[0,0,0,0,0]





            share|improve this answer













            You can nest the stream and map each level together, first by commas and then by the system line separator. Like,



            return Arrays.stream(BOARD).map(a -> Arrays.stream(a)
            
            .mapToObj(String::valueOf).collect(Collectors.joining(",", "[", "]")))
            
            .collect(Collectors.joining(System.lineSeparator()));


            I get



            [0,0,0,0,0]
            
[0,0,0,0,0]
            
[0,0,0,0,0]
            
[0,0,0,0,0]
            
[0,0,0,0,0]






            share|improve this answer












            share|improve this answer



            share|improve this answer










            answered Nov 14 '18 at 3:40









            Elliott FrischElliott Frisch

            154k1391180




            154k1391180

























                4














                You can alternatively do it using Arrays.streamas :



                Arrays.stream(BOARD)
                
        .map(aBOARD -> IntStream.of(aBOARD)
                
                .mapToObj(String::valueOf)
                
                .collect(Collectors.joining(",", "[", "]")))
                
        .forEach(board::add);





                share|improve this answer






























                  4














                  You can alternatively do it using Arrays.streamas :



                  Arrays.stream(BOARD)
                  
        .map(aBOARD -> IntStream.of(aBOARD)
                  
                .mapToObj(String::valueOf)
                  
                .collect(Collectors.joining(",", "[", "]")))
                  
        .forEach(board::add);





                  share|improve this answer




























                    4












                    4








                    4







                    You can alternatively do it using Arrays.streamas :



                    Arrays.stream(BOARD)
                    
        .map(aBOARD -> IntStream.of(aBOARD)
                    
                .mapToObj(String::valueOf)
                    
                .collect(Collectors.joining(",", "[", "]")))
                    
        .forEach(board::add);





                    share|improve this answer















                    You can alternatively do it using Arrays.streamas :



                    Arrays.stream(BOARD)
                    
        .map(aBOARD -> IntStream.of(aBOARD)
                    
                .mapToObj(String::valueOf)
                    
                .collect(Collectors.joining(",", "[", "]")))
                    
        .forEach(board::add);






                    share|improve this answer














                    share|improve this answer



                    share|improve this answer








                    edited Nov 14 '18 at 3:40









                    shmosel

                    36k43891




                    36k43891










                    answered Nov 14 '18 at 3:35









                    nullpointernullpointer

                    46.6k1199191




                    46.6k1199191























                        0














                        Collections' toString() already provides that notation in the AbstractCollection class. Just use:-



                        Arrays.stream(BOARD)
                        
        .forEach(ints -> System.out.println(
                        
                Arrays.stream(ints).boxed().collect(Collectors.toList()))
                        
        );


                        Or if you are happy to change int to Integer, you can even do:-



                        Arrays.stream(BOARD)
                        
        .forEach(ints -> System.out.println(Arrays.deepToString(ints)));





                        share|improve this answer






























                          0














                          Collections' toString() already provides that notation in the AbstractCollection class. Just use:-



                          Arrays.stream(BOARD)
                          
        .forEach(ints -> System.out.println(
                          
                Arrays.stream(ints).boxed().collect(Collectors.toList()))
                          
        );


                          Or if you are happy to change int to Integer, you can even do:-



                          Arrays.stream(BOARD)
                          
        .forEach(ints -> System.out.println(Arrays.deepToString(ints)));





                          share|improve this answer




























                            0












                            0








                            0







                            Collections' toString() already provides that notation in the AbstractCollection class. Just use:-



                            Arrays.stream(BOARD)
                            
        .forEach(ints -> System.out.println(
                            
                Arrays.stream(ints).boxed().collect(Collectors.toList()))
                            
        );


                            Or if you are happy to change int to Integer, you can even do:-



                            Arrays.stream(BOARD)
                            
        .forEach(ints -> System.out.println(Arrays.deepToString(ints)));





                            share|improve this answer















                            Collections' toString() already provides that notation in the AbstractCollection class. Just use:-



                            Arrays.stream(BOARD)
                            
        .forEach(ints -> System.out.println(
                            
                Arrays.stream(ints).boxed().collect(Collectors.toList()))
                            
        );


                            Or if you are happy to change int to Integer, you can even do:-



                            Arrays.stream(BOARD)
                            
        .forEach(ints -> System.out.println(Arrays.deepToString(ints)));






                            share|improve this answer














                            share|improve this answer



                            share|improve this answer








                            edited Nov 14 '18 at 3:43

























                            answered Nov 14 '18 at 3:37









                            KartikKartik

                            3,14931435




                            3,14931435






























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