Question

我正在尝试创建一个允许我更新对象值的小程序。但是我不断得到.class预期错误。

我的方法标记为static，允许我在main方法中调用这是我主要课程中的一种方法，我试图在我的学生班中调用一个方法来更新学分。

-- EXPLAIN
WITH z1 AS (
        SELECT za.id
        , CASE WHEN zcomment ilike '%text pattern 1' THEN 1
             WHEN zcomment ilike '%text pattern 2' THEN -1
             ELSE 0 END AS dir
        FROM zaction za
        WHERE zcomment ilike '%text pattern %'  -- <<== preselection to keep the CTE small
        )
SELECT za.*
FROM zaction za
JOIN (                                          -- <<== Join with subquery to give the optimiser some freedom
        SELECT za.id, z1.dir
        , SUM(z1.dir) OVER (ORDER BY za.id) AS yesno
        FROM zaction za
        LEFT JOIN z1 ON z1.id = za.id           -- <<== remerge with original set, whicha coulduse an index
        ) z2 ON z2.id = za.id AND z2.yesno > 0 AND z2.dir IS DISTINCT FROM 1
        ;

这是我的学生班级类型的方法

public static void doUpdate(MyStudent myStudent) {
  System.out.println("Enter credits: ");
  int numCredits = in.nextInt();
  System.out.println("Enter letter grade: ");
  String letterGrade = in.next();
  myStudent.takeClass(int numCredits, String letterGrade);
}

在调用takeClass

Answer 1

当您调用方法时，您不会传递参数的类型，只传递值。

替换：

myStudent.takeClass(int numCredits, String letterGrade);

使用

myStudent.takeClass(numCredits, letterGrade);

调用方法时的.class异常

1 个答案: