CODEWITHSUNDEEP
java-8
David
David

Reputation: 23

Is it possible to convert this method in to java 8 using streams? If yes how?

Suppose i have one method which takes two arrays of double type than takes a local variable 'sum' of double type with init value of zero. After that a for loop iterates from start to end and subtract like this a1[i] - b[i] and save result into another local variable called minus. Than do minus * minus and sum it with the existing value in sum variable and at the end sum. I am confuse how can i implement this in java 8 using streams. Can anybody help me?

public double calculate(double[] a1, double[] b2, int start, int end) {
  double sum = 0.0;
  for(int i = start; i < end; i++) {
    final double minus = a1[i] - b2[i];
    sum += minus * minus;
  }
  return sum;
}

Upvotes: 2

Views: 78

Answers (1)

Eugene
Eugene

Reputation: 121048

return IntStream.range(start, end)
            .mapToDouble(x -> a1[x] - b2[x])
            .map(x -> x * x)
            .sum();

Upvotes: 5

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