Populating a List with a contiguous range of integers

Question

I\'d like to have a list which contains the integers in the range 1 to 500. Is there some way to create this list using Guava (or just plain Java) without having to loop th

Answer 1

Btw. if it is only to be used in some sort of iteration, you could simply create a basic class which implements the Iterable interface, to skip the insertion altogether.

Something like this:

import java.util.Iterator;

public class IntegerRange implements Iterable {
    private int start, end;

    public IntegerRange(int start, int end) {
        if (start <= end) {
            this.start = start;
            this.end = end;
        } else {
            this.start = end;
            this.end = start;
        }
    }

    @Override
    public Iterator iterator() {
        return new IntegerRangeIterator();
    }

    private class IntegerRangeIterator implements Iterator {
        private int current = start;

        @Override
        public boolean hasNext() {
            return current <= end;
        }

        @Override
        public Integer next() {
            return current++;
        }
    }
}

Which could be used in some way like this:

Iterable range = new IntegerRange(1, 500);

for (int i : range) {
    // ... do something with the integer
}