How convert an int into an Array number by number

Question

I have one number, for example "1256", how can I convert it into an Array?

Actually, I use a constructor of class where I stock it.

public SecretBlock(int numbersToArray) {
    this.arrayOfNumbers = new int[AMOUNT];
    for (int i = AMOUNT - 1; i >= 0; i--) {
        this.arrayOfNumbers[i] = numbersToArray % 10;
        numbersToArray /= 10;
    }
}

Is there any fine/ adequate solution that may use Java 8 Stream?

Possible duplicate of [Convert integer to array of digits](https://stackoverflow.com/questions/8033550/convert-integer-to-array-of-digits) — Ron Nabuurs, Jun 01 '18 at 09:20
what is `AMOUNT`? also if you have `1256` how is the array suppose to look? [1, 2, 5, 6]? — Eugene, Jun 01 '18 at 09:21
You could convert the int to a string, loop over it and conver it back to int. — Ron Nabuurs, Jun 01 '18 at 09:22

Lino · Answer 1 · 2018-06-01T09:35:21.240

6

Your current solution is probably the most concise, but if you really want to use Java8 you can make use of following snippet:

int[] array = Arrays.stream(String.valueOf(numbersToArray).split(""))
    .mapToInt(Integer::parseInt)
    .toArray();

edited Jun 01 '18 at 09:35

answered Jun 01 '18 at 09:24

Lino

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1

or without a `Pattern` at all... via `Character#getNumericValue` – Eugene Jun 01 '18 at 09:31

score 6 · Accepted Answer · answered Jun 01 '18 at 09:29

6

 int[] result = String.valueOf(numbersToArray)
            .chars()
            .map(Character::getNumericValue)
            .toArray();

answered Jun 01 '18 at 09:29

Eugene

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or `.codePoints() .map(Character::getNumericValue)` – Ousmane D. Jun 01 '18 at 09:34
@Aominè Si senior – Eugene Jun 01 '18 at 09:34
Or `.map(i -> i - '0')` – Holger Jun 01 '18 at 14:53
I think you meant to write ```.mapToInt(...)``` rather than ```.map(...)``` – Valentin Ruano Jun 01 '18 at 23:39
@ValentinRuano what does `chars` return? – Eugene Jun 02 '18 at 00:51
@Eugene oups! I see,my bad, thanks for the correction, I guess I relied too much in the intuition that would return something like CharStream if that ever existed – Valentin Ruano Jun 02 '18 at 02:31

score 3 · Answer 3 · answered Jun 01 '18 at 09:24

3

Using java-8 one can do:

Pattern.compile("")
       .splitAsStream(String.valueOf(numbersToArray))
       .mapToInt(Integer::parseInt)
       .toArray();

answered Jun 01 '18 at 09:24

Ousmane D.

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Aah the `Pattern`. I always forget about that one. That is a very clean solution :) +1 – Lino Jun 01 '18 at 09:26

How convert an int into an Array number by number

3 Answers3