I am not understanding the reason, for having the compilation error for the below program. Where am I going wrong? I want to print the value of the string as output using method reference.
public class ConsumerDemo{
public static void main(String[] args) {
test("hello", (str)-> str::toUpperCase);
}
public static void test(String str, Consumer<String> consumer) {
consumer.accept(str);
}
}
test("hello", String::toUpperCase)
should be the correct syntax.
In order to print the upper case of the input, you can use:
String str = "hello"; // any input value
test(str.toUpperCase(), System.out::println);
String::toUpperCase will be ignored.
you cannot combine lambda syntax and method reference syntax as such.
You're either looking for:
test("hello", String::toUpperCase);
or:
test("hello", s -> s.toUpperCase());
but this then means the result of String::toUpperCase/s -> s.toUpperCase() is ignored hence, you'll need to perform something more useful. for example:
test("hello", s -> System.out.println(s.toUpperCase()));