Sum BigDecimal values in List with lambda [duplicate]

Question

I have a simple class:

class Simple {
    private String count;
    private BigDecimal amount;
    private String label;
}

and have a List: List<Simple> simples = new ArrayList<>(); how I can sum all amounts of all simples in list with Lambda in Java 8?

Answer 1

It is quite easy with a Stream and a reducer :

BigDecimal sum = simples
    .stream()
    .map(Simple::getAmount)
    .reduce(BigDecimal::add)
    .get();