扫描数字并将它们添加到列表和扫描答案并将其添加到变量答案

【问题标题】：Scanning numbers and adding them to list & scanning answer and adding it to variable扫描数字并将它们添加到列表和扫描答案并将其添加到变量
【发布时间】：2019-09-26 08:31:06
【问题描述】：

重点是我想在答案是“y”时将数字添加到数组中。当我输入 1 2 3 4 5 6 时，它只将最后 3 位添加到数组中（所以，它是 4 5 6），有时它甚至会跳过字符扫描。

代码如下：

int numbers1[99];
int i;
int n = 0; 
char answer = 'y'

while (answer == 'y')
    {
        n += 1;
        for (i = 0; i < n; i++)
        {
            printf("Insert a number: ");
            scanf("%d", &numbers1[i]);
            printf("Would you like to add more numbers? [Y/N]");
            scanf(" %c", &answer);
        }
    }

    printf("Numbers are following: ");

    for (i = 0; i < n; i++)
    {
        printf("%d, ", numbers1[i]);
    }

任何帮助将不胜感激。谢谢！

【问题讨论】：

你正在运行循环......两次。
这是一个好的开始：stackoverflow.com/help/how-to-ask。只是一个小指针，您的问题不包含您对代码的问题或问题。
@Dominik Sklyarov for 循环没有意义。

标签： c loops for-loop while-loop

【解决方案1】：

你只需要一个循环。将您的代码更改为

while (answer == 'y' && n < 99)    //check also for the array bound.
    {
            printf("Insert a number: ");
            scanf("%d", &numbers1[n++]);  //use 'n' as counter and increment it
            printf("Would you like to add more numbers? [Y/N]");
            scanf(" %c", &answer);
    }

注意：错误检查留给用户实施。

【讨论】：

【解决方案2】：

其中一个循环是多余的。那就是 for 循环在 while 循环的上下文中没有意义。

考虑到您要求用户在提示中输入'Y' 或'N'，但将变量answer 与字符'y' 进行比较。

我可以建议以下解决方案。

#include <stdio.h>
#include <ctype.h>

int main( void )
{
    enum { N = 99 };
    int numbers1[N];

    int n = 0;

    for ( char answer = 'Y'; n < N && answer == 'Y'; n++ )
    {
        printf("Insert a number: ");
        scanf("%d", &numbers1[n]);

        printf("Would you like to add more numbers? [Y/N] ");
        if ( scanf( " %c", &answer ) != 1 ) answer = 'N';
        answer = toupper( ( unsigned char )answer );
    }

    printf( "\nNumbers are following: " );

    for ( int i = 0; i < n; i++ )
    {
        if ( i != 0 ) printf( ", " );
        printf( "%d", numbers1[i] );
    }
    putchar( '\n' );
}

程序输出可能看起来像

Insert a number: 0
Would you like to add more numbers? [Y/N] y
Insert a number: 1
Would you like to add more numbers? [Y/N] 1
Insert a number: 2
Would you like to add more numbers? [Y/N] y
Insert a number: 3
Would you like to add more numbers? [Y/N] y
Insert a number: 4
Would you like to add more numbers? [Y/N] y
Insert a number: 5
Would you like to add more numbers? [Y/N] y
Insert a number: 6
Would you like to add more numbers? [Y/N] y
Insert a number: 7
Would you like to add more numbers? [Y/N] y
Insert a number: 8
Would you like to add more numbers? [Y/N] y
Insert a number: 9
Would you like to add more numbers? [Y/N] n

Numbers are following: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9

【讨论】：