import java.math.BigDecimal; import java.util.ArrayList; import java.util.Arrays; import java.util.stream.Collectors; class Test { private static final String[] decimalStrings = {"1.1", "+1.25"}; { Arrays.stream(decimalStrings).map(BigDecimal::new).reduce(BigDecimal::add).ifPresent(bd -> System.out.print("Sum is " + bd)); } void foo(final ArrayList<Pair> points) { points.stream().filter(p -> p.x > 0).collect(Collectors.toCollection(ArrayList::new)); } } class Pair { int x; }