C用于周期执行 [英] C For cycle execution

问题描述

我有一个简单的程序（基于示例从C编程语言编2第1.5.2节的书）的字符计数。该程序本身是很简单的，但我没有得到期望的结果。

I have a simple program (based on example from The C programming language ed. 2 section 1.5.2 book) for characters counting. The program itself is very simple, however I am no getting the expecting results.

似乎 numberOfChars 会递增两次，我没有不为什么......？

It seems that numberOfChars is incremented twice and I do not not why...?

我使用的cygwin + gcc编译器，请参阅图片：

I am using cygwin + gcc compiler, please see the image:

int main () {   
    int numberOfChars;  

    for(numberOfChars = 0; getchar() != EOF; numberOfChars++) 
        ;   //null statement

    printf("Number of chars = %d\n", numberOfChars);

    return 0;
}

感谢任何帮助： - ）

Thanks for any help :-)

推荐答案

创建一个文件，然后运行cygwin的OD程序，其次是C范例程序运行：

Create a file, then run the cygwin od program, followed by a run of the example C program :

od -x < testfile
a.out < testfile

然后，你可以看到什么和放大器;你有多少个字符的文件中有准确，避免意外。

Then you can see what & how many characters you had exactly in the file and avoid surprises.

辅助调试，如果我怀疑是出事了，我要补充的东西，如：

As a debugging aid, if I suspected something was wrong, I'd add something like :

int c; for(numberOfChars = 0; (c = getchar()) != EOF; numberOfChars++) 
    printf( "\0x%x", c);

要理解我的code是做处理。

To understand the processing my code was doing.

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