Lambda examples (1cd4c872) · Commits · examples / Head First Java 3rd Edition

src/main/java/ch10c/HelloLambda.java

+54 −1

Changes for src/main/java/ch10c/HelloLambda.java: 54 added lines, 1 removed line.
Original line number	Diff line number	Diff line
		@@ -2,11 +2,14 @@ package ch10c;

		import java.util.ArrayList;
		import java.util.List;
		import java.util.function.Consumer;
		import java.util.function.Function;
		import java.util.stream.Collectors;
		import java.util.stream.Stream;

		public class HelloLambda {
		public static void main(String[] args) {
		lambdaAsBehaviour();
		mandatoryTypes();
		}

		static void helloLambda() {
		@@ -32,4 +35,54 @@ public class HelloLambda {
		.limit(4)
		.collect(Collectors.toList());
		}

		static void longLambda() {
		List<String> strings = new ArrayList<>(List.of("I", "am", "a", "list", "of", "Strings"));

		List<String> result = strings.stream()
		.sorted(
		(String s1, String s2) -> {
		return s1.compareToIgnoreCase(s2);
		})
		.collect(Collectors.toList());
		System.out.println("result = " + result);
		}

		static void multilineLambda() {
		List<String> strings = new ArrayList<>(List.of("I", "am", "a", "list", "of", "Strings"));
		Stream<String> sorted = strings.stream().sorted(
		(str1, str2) -> {
		int l1 = str1.length();
		int l2 = str2.length();
		return l2 - l1;
		});

		List<String> result = sorted.collect(Collectors.toList());
		System.out.println("result = " + result);
		}

		static void noReturn() {
		List<String> strings = new ArrayList<>(List.of("I", "am", "a", "list", "of", "Strings"));
		strings.forEach(
		(String str) -> {
		String output = "str = " + str;
		System.out.println(output);
		}
		);
		}

		static void mandatoryTypes() {
		// if you remove String from the param here, the compiler doesn't know which method you want
		overloadedMethod((String str) -> System.out.println(str));
		}

		private static void overloadedMethod(Consumer<String> consumer) {
		consumer.accept("Something");
		}

		private static void overloadedMethod(Function<Integer, Integer> function) {
		function.apply(1);
		}


		}