Java 为什么getter方法没有';t返回任何对象';s属性?
我的程序应该返回两个不同对象的不同属性。在我的main方法中,我在创建新对象时将这些属性设置为参数。但是当我调用这些getter方法时(我在一个单独的类中编写了这些方法,如果需要的话,我可以发布该类),它不会返回所有属性。它只打印出第一个属性(也被设置为第一个参数),而不是其他两个值。我不知道我哪里做错了 我的代码:主类:Java 为什么getter方法没有';t返回任何对象';s属性?,java,arrays,object,return-value,getter-setter,Java,Arrays,Object,Return Value,Getter Setter,我的程序应该返回两个不同对象的不同属性。在我的main方法中,我在创建新对象时将这些属性设置为参数。但是当我调用这些getter方法时(我在一个单独的类中编写了这些方法,如果需要的话,我可以发布该类),它不会返回所有属性。它只打印出第一个属性(也被设置为第一个参数),而不是其他两个值。我不知道我哪里做错了 我的代码:主类: package main; public class Main { public static void main(String[] args) {
package main;
public class Main {
public static void main(String[] args) {
//creating object for book 1
Book book1 = new Book("The brief history of time", "111", new String[]{"S. hawking", "hawking's friends"});
//creating object for book 2
Book book2 = new Book("100 years of solitude", "222", new String[]{"G.marquez", "marquez's friend"});
System.out.println("All info for the first book: \n");
System.out.println("Name: " + book1.getName());
System.out.println("ISBN: " + book1.getIsbn());
System.out.println("Authors: " + book1.getAuthors());
System.out.println("\n\n");
System.out.println("All info for the second book: \n");
System.out.println("Name: " + book2.getName());
System.out.println("ISBN: " + book2.getIsbn());
System.out.println("Authors: " + book2.getAuthors());
}
}
图书类别:
package main;
public class Book {
//variables
private String name;
private String isbn;
private String[] authors;
//constructors
public Book(String name, String isbn, String[] authors) {
this.name = name;
this.isbn = name;
this.authors = authors;
}
//setters
public void setName(String name) {
this.name = name;
}
public void setIsbn(String isbn) {
this.isbn = isbn;
}
public void setAuthors(String[] authors) {
this.authors = authors;
}
//getters
public String getName() {
return name;
}
public String getIsbn() {
return isbn;
}
public String[] getAuthors() {
return authors;
}
}
您需要迭代
authors
数组以打印其中的字符串。大概是这样的:
System.out.println("All info for the first book: \n");
System.out.println("Name: " + book1.getName());
System.out.println("ISBN: " + book1.getIsbn());
for (String author : book1.getAuthors()) {
System.out.println("Author: " + author);
}
您的书中也有一个问题
类构造函数:
public Book(String name, String isbn, String[] authors) {
this.name = name;
this.isbn = name; // this.isbn is not name!
this.authors = authors;
}
public Book(String name, String isbn, String[] authors) {
this.name = name;
this.isbn = name; // you are setting isbn as name!
this.authors = authors;
}
必须是:
public Book(String name, String isbn, String[] authors) {
this.name = name;
this.isbn = isbn;
this.authors = authors;
}
当您想要打印字符串数组时,可以使用此选项
System.out.println(Arrays.toString(book1.getAuthors()));
public Book(String name, String isbn, String[] authors) {
this.name = name;
this.isbn = name; // this.isbn is not name!
this.authors = authors;
}
public Book(String name, String isbn, String[] authors) {
this.name = name;
this.isbn = name; // you are setting isbn as name!
this.authors = authors;
}
同时提供
Book
类的设计。你能发布Book类、你得到的实际输出和你期望的输出吗?Luiggi Mendoza,paolo,我已经编辑过了。你需要发布你得到的输出和你期望的输出。互联网没有水晶球!this.isbn=name;-真正地如果您想要漂亮的Spring Arrays,请使用java.util.Arrays.toString(book1.getAuthors()),或者使用Arrays.toString(book1.getAuthors()
)。