Can this be converted to IntStream?

Question

Can the below while loop be converted to IntStream?

Here modifiedNumber is an int. I want to refactor this to java8.

while (modifiedNumber > 0) {
    tempNumber = (int) ((modifiedNumber % 10) * Math.pow(10, count));
    alist.add(tempNumber);
    modifiedNumber = modifiedNumber / 10;
    count++;
}

Could you add to the question, what exactly are you trying to do with the code above? Are you trying to reverse a number> — Naman, Sep 02 '17 at 04:55
No I'm trying just split the numbers by decimal values. So like 123 is 3, 20,100 — user3310115, Sep 02 '17 at 05:20

score 0 · Answer 1 · answered Sep 02 '17 at 05:59

Well, not very sure of the declarations used for the variables used in your code shared, but to transform the above code to use IntStream, you can attempt something like(declarations mine) :

final int[] modifiedNumber = {123};
final int len = String.valueOf(modifiedNumber[0]).length();
ArrayList<Integer> aList = new ArrayList<>();
final int[] count = {0};
IntStream.range(0,len).forEach(mn -> {
    double pow = Math.pow(10, count[0]);
    int tempNumber = (int) ((modifiedNumber[0] % 10) * pow);
    aList.add(tempNumber);
    modifiedNumber[0] = modifiedNumber[0] / 10;
    count[0]++;
});

System.out.println(aList);

Note: Most of the integer values are converted to final single valued array to be consumed within the streams.

So based on this, does using streams here make any sense in this case? — user3310115, Sep 02 '17 at 06:37
@user3310115 the effectiveness of using streams is mostly when you want to execute oprations in parrallel. Good read over forEach vs for each : - https://stackoverflow.com/a/16635489/1746118 — Naman, Sep 02 '17 at 07:04

alirabiee · Answer 2 · 2017-09-02T06:12:12.043

Here is a possible way to do it. You could also pass multiple numbers to Stream.of() and the output will be a stream of the dissection of all those numbers.

final Stream< Integer > integerStream = Stream.of( modifiedNumber ).flatMap( n -> {
    final List< Integer > aList = new LinkedList<>();

    int tempNumber, count = 0;

    while ( n > 0 ) {
        tempNumber = ( int ) ( ( n % 10 ) * Math.pow( 10, count ) );
        aList.add( tempNumber );
        n = n / 10;
        count++;
    }

    return aList.stream();
} );

Can this be converted to IntStream?

2 Answers2