1
JavaIntermediate#java8
JavaIntermediate#java8
What is a functional interface?
An interface with exactly one abstract method. Marked optionally with @FunctionalInterface. Examples: Runnable, Callable, Comparator, Function, Predicate, Consumer, Supplier.
Example
@FunctionalInterface
interface Calculator { int operate(int a, int b); }
Calculator add = (a, b) -> a + b;
add.operate(2, 3); // 5