Lambda: Consumer performs a side effect and returns nothing

A Consumer's single abstract method takes an argument and returns void, so it is used purely for its side effect, such as printing, rather than for producing a value.

Code

Consumer<String> printer = s -> System.out.println("Consumed: " + s);
List<String> names = List.of("Ann", "Bo");
for (String n : names) {
    printer.accept(n);
}

Output

Consumed: Ann
Consumed: Bo