Question

public class ReferenceTest {
    public static void main(String[] args) {

        String[][] names = {{"George","Hampton"},{"Marc", "Empten"},{"Levin", "Lian"}};

        Object oneperson; //Reference to one object of the 2D Array

        oneperson = names[1]; 

        //Output should be Marc Empten
        System.out.println(oneperson.toString()); //[Ljava.lang.String;@11890d

    }
}

是否可以在java中创建这样的引用？所以我可以保存一个数组元素（

{＆＃34;马克＆＃34;＆＃34; Empten＆＃34;}

）来自阵列？

所以我只能使用oneperson变量来表示＆＃34; Marc Empten＆＃34;？我不知道如何实现这一点。它甚至可能吗？

Answer 1

如果您只想使用Arrays.toString()方法打印数组。但是，更好的方法是制作一个包含两个部分的名称。然后使用数组列表来存储名称。像

class Name{
    private String firstName;
    private String lastName;

    public Name(String firstName, String lastName) {
        this.firstName = firstName;
        this.lastName = lastName;
    }

    @Override
    public String toString() {
        return "{" + firstName + ", " + lastName
                + "}";
    }
    // Getters & Setters
}

public class Sample {

    public static void main(String[] args) throws JsonProcessingException {
        List<Name> names = new ArrayList<Name>(Arrays.asList(new Name[] { new Name("George","Hampton"), new Name("Marc", "Empten"), new Name("Levin", "Lian")}));
        System.out.println(names.get(1)); // Prints {Marc, Empten}

    }
}

Answer 2

你必须写下这样的东西：

public class ReferenceTest {
    public static void main(String[] args) {
        // An array of arrays of Strings
        String[][] names = {{"George","Hampton"},{"Marc", "Empten"},{"Levin", "Lian"}};
        // An array of Strings
        String[] marc = names[1]; 
        //Output is Marc Empten
        System.out.println(marc[0] + " " + marc[1]);
    }
}

仅当您确定内部数组始终包含2个元素时，此方法才有效。如果没有，你将不得不使用循环来打印名称（例如，姓氏有3个部分）：

final String[][] names =
    { { "George", "Hampton" }, { "Marc", "Empten" }, { "Levin", "Lian" }, { "John", "James", "Rambo" } };

for (final String[] name : names) {
    for (final String partial : name) {
        System.out.print(partial);
        System.out.print(" ");
    }

    System.out.println();
}

Answer 3

这样做：

System.out.println(Arrays.toString((Object[])oneperson));

参考2D阵列元素

3 个答案: