将数据从文件读入2d数组 [英] reading data from a file into a 2d array
问题描述
好的，如果我的第一篇帖子对我来说很容易，而且我已经使用了几个星期的
C.我正在开发一个程序，目前这个项目需要我将.dat文件中的数据读入二维数组然后再打开
打印出二维数组的内容到屏幕。我还需要
将数据附加到.dat文件，但现在大部分时间我都在担心
将信息输入到2d数组中。我的.dat文件看起来像这样
1 20000
2 30000
3 40000
等。第一个代表身份证号码，第二个代表
重量。
#include< stdio.h>
main（）
{
FILE * pRead;
int array [20] [3];
pRead = fopen（" test.dat"，" r"）;
if（pRead == NULL）
printf （\ nFile无法打开\ nn;）
其他
printf（&\\; \ n \\ n \\ n的test.dat \ n的内容） \ n"）;
fscanf（pRead，"％s，％s"，数组）;
while（！feof（pRead））
{
printf（"％s％s \ n"，array）;
fscanf（pRead，"％s， ％s"，array）;
}
}
我知道我需要使用for循环或者某种想法，以便我可以在列中读取
，然后在行中读取。我真的在这里画了一个空白
如何让它工作。有人能指出我正确的方向吗？
因为现在我的输出是这样的：
11
20002000
22
30003000
等
此外，如果我使用％d而不是％在这里，我得到了分段错误。可以
任何人解释为什么会发生这种情况？谢谢。
你介意告诉我你为什么使用多dimintinal数组吗？对我来说
似乎你也是
使用整数数组并用字符串填充它？
< blockquote> da*********@gmail.com 写道：
你介意告诉我你为什么使用多dimintinal数组吗？对我来说
似乎你也是使用整数数组并用字符串填充它？
请阅读< http：// cfaj .freeshell.org /谷歌/取代。谢谢。
-
Keith Thompson（The_Other_Keith） ks *** @ mib.org < http://www.ghoti.net/~kst>
圣地亚哥超级计算机中心< *> < http://users.sdsc.edu/~kst>
我们必须做点什么。这是事情。因此，我们必须这样做。
2006-02-23，yourmycaffiene< dd **** @ gmail.com>写道：好的，如果我的第一篇帖子对我来说很容易，而且我只用了几个星期就用了。我正在研究一个程序，它目前要求我将.dat文件中的数据读入二维数组，然后将二维数组的内容打印到屏幕上。我还需要
将数据附加到.dat文件中，但现在大部分时间我都在担心将信息输入到2d数组中。我的.dat文件看起来像这样一个20000
2 30000
3 40000
等第一个代表身份证的号码和第二个号码
#include< stdio.h>
main（）
{
FILE * pRead;
int数组[20] [3];
pRead = fopen（" test.dat"，" r"）;
if（pRead == NULL）
printf（" ; \ nFile无法打开\ n"）;
其他
printf（" \\\
Contents of test.dat \ n \ n"）;
fscanf（pRead，"％s，％s"，array）;
while（！feof（pRead））
{/> printf（"％s％s \\ \\ n，数组）;
fscanf（pRead，"％s，％s"，数组）;
}
}
我知道我需要使用for循环或某些东西来实现这个想法，这样我才能在列中读取然后读取行。我真的在这里画了一个空白
如何让它工作。有人能指出我正确的方向吗？
因为现在我的输出结果是这样的：
11
20002000
22
30003000
等
另外，如果我在这里使用％d而不是％s，我会遇到分段错误。谁能解释为什么会发生这种情况？谢谢。
查看此代码并从那里开始工作：
#include< stdio.h>
main（）
{
unsigned long a，b;
FILE * pRead = fopen（" test.dat"，" r"）;
if（pRead == NULL）
printf（" File无法打开\ n"）;
其他
printf（" test.dat的内容：\ n"）;
while（！feof（pRead））{
fscanf（pRead，"％u％u \ n"，& a，& b）;
printf（"％u％u \ nn，a，b）;
}
}
一些指示可以帮助你：fcanf可以为你做转换
：如果你使用fscanf就使用它。你正在阅读字符串和
然后将它们存储在int中。存储 - 这是顽皮的，非常好的b $ b不洁净。尝试处理类型并保持它们
一致。虽然C可以并且确实允许您将数据粘贴在错误的
类型内存中。这是一个非常糟糕的主意。
作为练习我们留下的阵列中的存储空间:)
-
删除evomer回复
Okay, this if my first post so go easy on me plus I''ve only been using
C for a couple of weeks. I''m working on a program currently that
requires me to read data from a .dat file into a 2d array and then
print out the contents of the 2d array to the screen. I wil also need
to append data to the .dat file but mostly right now I''m worrying about
getting the info into the 2d array. My .dat file looks like this
1 20000
2 30000
3 40000
etc. The first number standing for an ID and the second standing for a
weight.
#include <stdio.h>
main()
{
FILE *pRead;
int array[20][3];
pRead = fopen("test.dat", "r");
if (pRead==NULL)
printf("\nFile cannot be opened\n");
else
printf("\nContents of test.dat\n\n");
fscanf(pRead,"%s,%s", array);
while ( !feof(pRead) )
{
printf("%s%s\n", array);
fscanf(pRead, "%s,%s", array);
}
}
I know I need to use a for loop or something to that idea so that I can
read in the column and then the row. I''m really drawing a blank here on
how to get that working. Could someone point me in the right direction?
Cause right now my output is coming out like this :
11
20002000
22
30003000
etc.
Also, if I use %d instead of %s here, I get segmentation faults. Can
anyone explain why this is happening? Thanks.
do you mind telling me why you used a multi-dimintinal array? to me it
seems also you are
using an integer array and filling it with strings?
da*********@gmail.com writes:do you mind telling me why you used a multi-dimintinal array? to me it
seems also you are
using an integer array and filling it with strings?
Please read <http://cfaj.freeshell.org/google/>. Thanks.
--
Keith Thompson (The_Other_Keith) ks***@mib.org <http://www.ghoti.net/~kst>
San Diego Supercomputer Center <*> <http://users.sdsc.edu/~kst>
We must do something. This is something. Therefore, we must do this.
On 2006-02-23, yourmycaffiene <dd****@gmail.com> wrote:Okay, this if my first post so go easy on me plus I''ve only been using
C for a couple of weeks. I''m working on a program currently that
requires me to read data from a .dat file into a 2d array and then
print out the contents of the 2d array to the screen. I wil also need
to append data to the .dat file but mostly right now I''m worrying about
getting the info into the 2d array. My .dat file looks like this
1 20000
2 30000
3 40000
etc. The first number standing for an ID and the second standing for a
weight.
#include <stdio.h>
main()
{
FILE *pRead;
int array[20][3];
pRead = fopen("test.dat", "r");
if (pRead==NULL)
printf("\nFile cannot be opened\n");
else
printf("\nContents of test.dat\n\n");
fscanf(pRead,"%s,%s", array);
while ( !feof(pRead) )
{
printf("%s%s\n", array);
fscanf(pRead, "%s,%s", array);
}
}
I know I need to use a for loop or something to that idea so that I can
read in the column and then the row. I''m really drawing a blank here on
how to get that working. Could someone point me in the right direction?
Cause right now my output is coming out like this :
11
20002000
22
30003000
etc.
Also, if I use %d instead of %s here, I get segmentation faults. Can
anyone explain why this is happening? Thanks.
Have a look at this code and work from there:
#include <stdio.h>
main()
{
unsigned long a,b;
FILE * pRead = fopen("test.dat", "r");
if (pRead==NULL)
printf("File cannot be opened\n");
else
printf("Contents of test.dat : \n");
while ( !feof(pRead) ){
fscanf(pRead,"%u %u\n", &a,&b);
printf("%u %u\n",a,b);
}
}
Some pointers to help you on the way : fcanf can do the conversions
for you : use it if you use fscanf. You were reading in strings and
then storing them in "int" storage - this is naughty and very
unclean. Try to get a handle on the types and keep them
concistent. While C can and does allow you to stick data in the wrong
"type memory" it is a very bad idea.
The storage in the array we leave as an excercise :)
--
Remove evomer to reply
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