小编use*_*719的帖子

我做了一个简单的函数来计算数字的阶乘,但从数字34返回0.它应该是51号.

   public class Métodos {
       public int factorial (int numero ){

          if ((numero <0)||(numero>50)){

           return 0;        
          } 

          else if ((numero == 0)||(numero == 1)){

           return 1;   
          }

          else{

           return numero * factorial(numero -1); 


          }

    }




    }

谢谢 !

编辑:

好的,我怎么检查呢？

因为它说int不能转换为bigInteger.

 public static void main(String[] args) {
        // TODO code application logic here
         Métodos metod = new Métodos();
         System.out.print("El resultado es : " + metod.factorial(-12)+ "\n");
         System.out.print("El resultado es : " + metod.factorial(-1)+ "\n");
         System.out.print("El resultado es : " + …

嗨,我在mysql phpMyAdmin中创建表时出现1022错误.错误发生在最后一个表"usercoment"上:

解决方案编辑:好的,我已经有一个命名的Constraint键IdMovie,所以我重命名,它工作正常.感谢你们.

以下是表格:

CREATE TABLE IF NOT EXISTS `WhichMovie`.`UserComent` (
  `IDComent` INT NOT NULL,
  `IDUser` INT NOT NULL,
  `IDMovie` INT NOT NULL,
  `date` TIMESTAMP NOT NULL,
  PRIMARY KEY (`IDComent`, `IDUser`, `IDMovie`, `date`),
  INDEX `idUser_idx` (`IDUser` ASC),
  INDEX `idMovie_idx` (`IDMovie` ASC),
  CONSTRAINT `IdComent`
    FOREIGN KEY (`IDComent`)
    REFERENCES `WhichMovie`.`Coment` (`idComent`)
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  CONSTRAINT `IiUser`
    FOREIGN KEY (`IDUser`)
    REFERENCES `WhichMovie`.`User` (`idUser`)
    ON DELETE CASCADE
    ON UPDATE CASCADE,
  CONSTRAINT `IdMovie`
    FOREIGN KEY (`IDMovie`)
    REFERENCES `WhichMovie`.`Movie` (`idMovie`)
    ON …