Given that I have two arrays in Java, A and B I want to add the elements, element-wise, which results in a sum array. Doing this implicitly with a loop is easy but I was wondering if there was a more elegant solution, perhaps with the guava collections or build in java utils. Or perhaps a python-ish way which makes is easy with list comprehensions.
Example:
A = [2,6,1,4]
B = [2,1,4,4]
sum = [4,7,5,8]
You can do it like this:
private void sum() {
int a[] = {2, 6, 1, 4};
int b[] = {2, 1, 4, 4};
int result[] = new int[a.length];
Arrays.setAll(result, i -> a[i] + b[i]);
}
This will first create int result[] of the correct size.
Then with Java 8, released yesterday, the easy part comes:
Arrays.setAll(int[] array, IntUnaryOperator);IntUnaryOperator you can create a lambda mapping the index to the result, in here we choose to map i to a[i] + b[i], which exactly produces our sum.Arrays.parallelSetAll
You can use java8 stream and operation on array like this:
//in this example a[] and b[] are same length
int[] a = ...
int[] b = ...
int[] result = new int[a.length];
IntStream.range(0, a.length)
.forEach(i -> result[i] = a[i] + b[i]);
array