Java开发网 - 各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.)

Topic: 各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.)

1.各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.)

Posted by: wwd1015
Posted on: 2005-07-23 19:39

请使用准确的文字描述作为标题
Your next post without a proper Subject will be removed.

Do you have problem in reading the error messages issued by javac?
Math.round(double) returns a long, so it should be:
long x = Math.round (Math.PI * 20.0);

In addition, you would like to add the public keyword:
public class No

Original subject : 各位大哥看看有什么错，小弟我看不出。

 
class No {
  public static void main (String [] args) {
      int x = Math.round (Math.PI * 20.0);
      System.out.println ;
  }
}

2.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: wwd1015]	Copy to clipboard
Posted by: wwd1015 Posted on: 2005-07-24 08:18 谢谢了标题我会注意的。代码看书的，没想到书都错了。顺便再请教一下long是什么类型的变量，还有加不加public好像没什么不同啊。

3.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: wwd1015]	Copy to clipboard
Posted by: 阳光地带 Posted on: 2005-07-26 09:47 long 是长整型吧. 加了public后,类名和文件名要同名的.不加public,文件名可以随便取了.

4.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: wwd1015]	Copy to clipboard
Posted by: FlowerBud Posted on: 2005-07-26 15:31 Math.PI是double型的,你的x也应该定义为double型,或者把Math.PI*20.0强制转换成int型

5.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: FlowerBud]	Copy to clipboard
Posted by: why Posted on: 2005-07-26 19:41 FlowerBud wrote: Math.PI是double型的,你的x也应该定义为double型,或者把Math.PI*20.0强制转换成int型 Read carefully! It's Math.round !!

6.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: wwd1015]	Copy to clipboard
Posted by: wwd1015 Posted on: 2005-07-27 08:10 class No { public static void main (String [] args) { int x = (int) Math.round (Math.PI*20.0); System.out.println ; } } 这样可以吗？好像和Math.round不同吧.long类型的有什么特点，还是不知道。还有各位能推荐几本好书吗，包含基础知识的，谢谢了。

7.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: wwd1015]	Copy to clipboard
Posted by: IT_liuxue2005 Posted on: 2005-07-29 17:14 这个哥们真逗!你是不是刚来学啊!这多简单啊!太基础了!

8.Re:各位大哥看看有什么错，小弟我看不出。(Solved, pls ignore.) [Re: wwd1015]	Copy to clipboard
Posted by: wangdingyuan Posted on: 2005-08-01 14:56 <Thinking in java>