Java开发网 - [菜鸟cargo的问题]20060315(Re: length)

Topic: [菜鸟cargo的问题]20060315(Re: length)

1.[菜鸟cargo的问题]20060315(Re: length)	Copy to clipboard
Posted by: cargo Posted on: 2006-03-15 14:41 我是新手，看着CORE JAVA 学习入门，遇到一个问题，请大家别笑它简单，对我来说还是问题呢.... 谢谢！

2.Re:[菜鸟cargo的问题]20060315 [Re: cargo]

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Posted by: Skybus
Posted on: 2006-03-15 15:04

It's not recommended to post you code like this . Post your code using text mode!

For your question.both balance and balance[i] are array variables;They have no difference in syntax,but they differ in semantce. balance.lenght means the lenght of the wole array,but balance[i].lenght means the lenght of the array banlance[i].They can't be exchanged each other!

3.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]

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Posted by: why
Posted on: 2006-03-15 17:30

Skybus:
Thanks but please try to spell check before you post.

For your question, both balance and balance[i] are array variables.
They have no difference in syntax, but they differ in semantics.
balance.length means the length of the "whole array" (array of arrays), but balance[i].length means the length of the array balance[i]. They can't be exchanged with each other!

BTW, we seldom say "it's recommendatory to do something", but rather "it's recommended to do something", or "something is recommendatory to somone".

cargo:
Indeed it's not recommended to post your source code listing as an image. If it is really necessary, you could use a lower JPEG quality factor (say, 70%) to reduce the size of the image.
Thanks.

4.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]	Copy to clipboard
Posted by: leior Posted on: 2006-03-15 18:15 balance.length:NYEARS balance[i].length:NRATES

5.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]	Copy to clipboard
Posted by: surroad Posted on: 2006-03-15 18:40 二维数组不同维的长度

6.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]	Copy to clipboard
Posted by: Skybus Posted on: 2006-03-15 18:52 to why: Thanks a lot for your attention,It's my careless mistake,I'll try to avoid it in the fulture !

7.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]

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Posted by: cargo
Posted on: 2006-03-16 01:08

谢谢大家了，
可是对二维数组自动填充的时候：
for (int i=1;i<balance.length;i++)
{
   for (int j=0;j<balance[i].length;j++)
   {
     double oldBalance=balance[i-1][j];
     double interest=oldBalance*interestRate[j];
     balance[i][j]=oldBalance+interest;
   }
}

二维数组可以理解成“小数组的数组”，如果中间那个“for”循环是给每“行”小数组按列赋值的话，那么外面的“for”循环就是确定了小数组的行数。
那么第一个for中的“i<balance.length”似乎不太合理，它的意义是整个二维数组中的所有小数组的个数，而不是行数，对吗？

8.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]

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Posted by: jackyangf
Posted on: 2006-03-17 14:54

首先 balance 是一个数组那么 balance.length 是一个整型，表示这个数组的长度
特别一点的是，这个balance数组里的元素也是数组，那么他们也有各自的长度
可以肯定的一点是：这个大数组的长度（包含的小数组的个数）肯定不需要和小数组的长度一致

这些是对 balance 数组的说明
另外一点是对数组这种类型来说，它的长度 .length 是一个只读的变量；不能修改的。所以你没有办法用任何东西来替换它，除非你不要这个数组了，另外在创建一个长度不同的。

9.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]	Copy to clipboard
Posted by: jackyangf Posted on: 2006-03-17 14:57 balance[0] lenth = 5 O O O O O \ balance[1] lenth = 5 O O O O O - balance length = 3 balance[2] lenth = 5 O O O O O /

10.Re:[菜鸟cargo的问题]20060315(Re: length) [Re: cargo]	Copy to clipboard
Posted by: cargo Posted on: 2006-03-20 16:23 谢谢jackyangf的回答，我了解了：对于这个balance树组，balance.lentgh的数量不是大树组中所有数字的数量，而是其中的树组的数量，也就是大树组中的元素的“行数”！再次谢谢jackyangf和上面所有的大虾~~~~