c - C中的字符计数器

问题描述

这段 C 语言代码应该计算表中等于 A 的所有字符..但它不起作用我需要帮助才能找到问题！~~我首先使用for循环读取用户给出的表格字符，然后我使用另一个for循环来计算等于A的字符数~~

请有任何建议

#include <stdio.h>
#include <stdlib.h>

int main()
{
    char T[100],A;
    int i,N,b=0;
    
    printf("give the number of your table's columns \n");
    scanf("%d", &N);

    if (N > 0 && N <= 100) {
        for (i; i < N; i++) {
            scanf("%c", &T[i]);

            printf("give the character of the column number %d \n", i);
            scanf("%c",&T[i]);
        }
     
        for (i; i < N; i++) {
            if (T[i] = 'A') b++; 

            printf("the number of characters equal to A is %d",b);
        }
        return 0;
    }
}

标签： csyntax

“应该计算一个表中所有等于 A 的字符 ..但它不起作用我需要帮助才能找到问题！！”

编译器警告将帮助您找到问题所在。
如果您在编译时没有看到警告，请将您的编译器设置为显示它们。（例如在 GCC中使用-Wall）

在打开警告的情况下进行编译时，您应该会在编译时看到与此类似的信息：

Build Status (so.prj - Debug)
 s0_15.c - 3 warnings
  22, 22    warning: using the result of an assignment as a condition without parentheses 
  22, 22    note: place parentheses around the assignment to silence this warning
  22, 22    note: use '==' to turn this assignment into an equality comparison
  7, 17     warning: unused variable 'A' 
  14, 14    warning: variable 'i' is uninitialized when used here 
  8, 10     note: initialize the variable 'i' to silence this warning

此外，当下降到第二个for()循环时，i再次没有初始化，而是保留完成第一个循环时的值。它需要重新初始化为零才能使第二个循环正常工作......（注意，我的编译器没有标记这个，幸运的是我被告知学习如何设置和使用我在这里做的断点，让我i在运行时发现的价值。

按照上述警告提供的指导，进行了修改以允许代码运行，并按照您描述的方式进行操作。

有关对上述警告的响应，请参阅在线评论：

int main(void)//added void to match accepted prototype of main
{
    char T[100] = {0},A;//A is not used, should be deleted
                        //initialize array to all zeros.
    int i=0,N=0,b=0;//initialized i (and N)
    
    printf("give the number of your table's columns \n");
    scanf("%d", &N);

    if (N > 0 && N <= 100) {
        for (i; i < N; i++) {
            scanf("%c", &T[i]);

            printf("give the character of the column number %d \n", i);
            scanf("%c",&T[i]);
        }
        // `i` is already equal to N here.  it will never enter the loop
        //for (i; i < N; i++) {         
        for (i = 0; i < N; i++) {//initialized i to zero
          //if (T[i] = 'A') b++;//this is not what you want
            if (T[i] == 'A') b++; //replace assignment '=' 
                                  //with    comparison '==' operator
            //Note, optionally move the following printf() statement to below 
            //the loop so it is called only once after counting is done.
            printf("the number of characters equal to A is %d\n",b);//added '\n' for readability of output.
        }
        //return 0;// not here...
    }
    return 0;// ...but here
}

c - C中的字符计数器

问题描述

解决方案

推荐阅读