2018-10-18 Java toString() 方法的运用

因为在java中 Object类是基类，所以每个类都会有toString方法，System.out.println（Object）实际上就是调用 object的 toString 方法

public class Part1_1{
  public static void main(String[] args) {
    Author author1 = new Author("Richard Hartley", "123456@gamil.com", 'M');
    Book aBook = new Book("Multiple View Geometry",author1,100,10);
    Author author2 = new Author("Peter", "456789@gamil.com", 'F');
    aBook.AddAuthor(author2);
    System.out.print(aBook.toString());
    System.out.print("\n");
    aBook.RemoveAuthor("Peter");
    System.out.println(aBook); // 调用 aBook 的 toString（）
  }
}

  //重写过的 toString() 方法
  public String toString(){
    String str = "Author[ name = "+this.getName()+", email = "+this.getEmail()+", gender = "+this.getGender()+"]";
    return str;
  }

输出

Book[ name = Multiple View Geometry,[Author[ name = Richard Hartley, email = 123456@gamil.com, gender = M], Author[ name = Peter, email = 456789@gamil.com, gender = F]], price = 100.0, qty = 10]

Book[ name = Multiple View Geometry,[Author[ name = Richard Hartley, email = 123456@gamil.com, gender = M]], price = 100.0, qty = 10]

参考资料
https://zhidao.baidu.com/question/16425045.html
https://zhidao.baidu.com/question/582453879.html?qbl=relate_question_0&word=toString%28%29

刘月林
写于浙江宁波
20181018