Converting from <Datatype1>[] to <Datatype2>[]

Anonymous User 2049 09 Jul 2015

Is it possible to convert from a list of datatypes without going through the trouble of looping through the entire list.

I.e:b = {"1", "2"};

Integer[] a = (Integer[]) b; //not actually runnable

Not really necessary, but it would be nice.

Ask by Anonymous User

Updated 09 Jul 2015

1 Answers

Anonymous User 09 Jul 2015

In Java 8, you can do

Integer[] integerArray = 
    Stream.of(stringArray)
          .map(Integer::parseInt)
          .toArray(Integer[]::new);

If you want an int-Array, you can do:

int[] intArray = 
Stream.of(stringArray)
      .mapToInt(Integer::parseInt)
      .toArray();

Stream.of() creates a stream from the array. map maps every element of the stream to an Integer using Integer::parseInt. Using mapToInt, you can create an Intstream, which is a specialization of streams for integer primitives. Integer[]::new is a method reference to an array constructor.

This assumes all elements of the array are parseable, if not it will throw an exception.

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Converting from <Datatype1>[] to <Datatype2>[]

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