Java中初始化List集合的6种方式详解

List<String> languages = new ArrayList<>();
languages.add("Java");
languages.add("PHP");
languages.add("Python");
System.out.println(languages);

List<String> jdks = Arrays.asList("JDK6", "JDK8", "JDK10");
System.out.println(jdks);

List<String> numbers = new ArrayList<>(Arrays.asList("1", "2", "3"));
numbers.add("4");
System.out.println(numbers);

List<String> apples = Collections.nCopies(3, "apple");
System.out.println(apples);

List<String> dogs = new ArrayList<>(Collections.nCopies(3, "dog"));
dogs.add("dog");
System.out.println(dogs);

List<String> cat = Collections.singletonList("cat");
System.out.println(cat);

List<String> cat = Collections.emptyList("cat");

List<String> names = new ArrayList<>() {{
    add("Tom");
    add("Sally");
    add("John");
}};
System.out.println(names);

List<String> colors = Stream.of("blue", "red", "yellow").collect(toList());
System.out.println(colors);

import static java.util.stream.Collectors.toList;

List<String> cups = List.of("A", "B", "C");
System.out.println(cups);