Question

我是Java的Begginer，在这里有如此深刻的见解。 int给出了一个nullexception，我不认为在这里使用Integer是一个很好的做法，因为稍后我将不得不使用int Pages但因为它将是Integer我将不得不继续使用（Integer.valueOf（17）== 17）;只是为了使Integer成为一个int，因为Integer无法与int进行比较。

public class TestBook {

  public static void main(String[] args) {


    // = = = =
    // Instantiating an empty Book object; for example: Book1, for testing
    Book  Book1 = new Book("Renewable Energy","John Smith",209);
    Book  Book2 = new Book("Harry Potter PS ","JK Rowling",null);
    Book  Book3 = new Book("Harry Potter PA ","JK Rowling",-1);

    System.out.println("Test for object Book1");
    System.out.println("=====================");
    System.out.println(Book1.printBook());
    System.out.println(Book2.printBook());
    System.out.println(Book3.printBook());

}
}

// Mainclass

Declare @MyList table
(
    PhotoId INT
)

DECLARE @Id INT
INSERT INTO @MyList
Select PhotoId From tblContactAndtblContactPhoto  Where  ContactId=@Id;

DELETE From tblContactAndtblContactPhoto  Where  ContactId=@Id;
Delete tblContactPhoto Where Id IN(SELECT PhotoId FROM @MyList)

如何将可变数量从一个类/构造函数导入另一个？

0 个答案: