package lambda.lambda3; public class GenericMain1 { public static void main(String[] args) { StringFunction upperCase = s -> s.toUpperCase(); String result1 = upperCase.apply("hello"); System.out.println("result1 = " + result1); NumberFunction square = n -> n*n; Integer result2 = square.apply(3); System.out.println("result2 = " + result2); } @FunctionalInterface interface StringFunction{ String apply(String s); } @FunctionalInterface interface NumberFunction{ Integer apply(Integer n); } }