Scala: from Array[String] to Array[Array[String]]

Question

I have an Array[String] in scala like this

my_array: Array[String] = Array(RED;BLUE, RED;PINK, RED;ORANGE, RED;WHITE, RED;YELLOW, 
RED;GREY,GREEN;BLUE, GREEN;PINK, GREEN;BROWN, GREEN;ORANGE, GREEN;WHITE, GREEN;YELLOW, GREEN;GREY)

and I need to get this result

my_new_array: Array[Array[String]] = Array(Array(RED;BLUE, RED;PINK, RED;ORANGE, RED;WHITE,RED;YELLOW, RED;GREY), 
Array(GREEN;BLUE, GREEN;PINK, GREEN;BROWN, GREEN;ORANGE, GREEN;WHITE, GREEN;YELLOW, GREEN;GREY), 
Array(RED;BLUE, GREEN;BLUE), Array(RED;PINK, GREEN;PINK), 
Array(RED;ORANGE, GREEN;ORANGE), Array(RED;WHITE, GREEN;WHITE),    
Array(RED;YELLOW, GREEN;YELLOW), Array(RED;GREY, GREEN;GREY))

These should be te steps

get a list of unique colors. this means I have to split by ";" each string
once I have this list I have to create a new Array contained the original strings grouped by each single color

Does anyone have an hint?

Gabriele Petronella · Accepted Answer · 2015-05-28 09:18:57Z

5

Provided I've understood your question correctly, this should work (probably not the most efficient solution ever)

myArray
.flatMap(_.split(';'))                      // get all the colors
.distinct                                   // get the unique set of colors
.map(color => myArray.filter(_.contains(color)))  // map each color to each group containing it

I'm using contains assuming that for "YELLOW" you want to match both "YELLOW";"RED" and "RED";"YELLOW".

In case you want to match only the former, you can use startsWith intead.

edited May 28, 2015 at 9:18

answered May 27, 2015 at 15:46

Gabriele Petronella

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1 Comment

mohit Over a year ago

x should be myArray in the last map statement. x does not exist.

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