c - 从最大大小为 100 的数组中获取用户输入后，如何检查用户输入了多少个值？

Question

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Answer 1

这不起作用，因为带有 "%d" 说明符的 scanf 将跳过 \n，您可以消耗所有白色空格字符，用fgetc()搜索'\n'，可以返回最后一个不是'\n'的空白字符使用 ungetc() 到流，所以这个程序可能会做你需要的

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

int main()
{
    int a[100];
    int i;
    int result;

    result = 1;
    i      = 0;
    while ((i < 100) && (result == 1))
    {
        int chr;

        /* 
         * consume all whitespace characters left by previous scanf, 
         * stop if one of them is '\n' 
         */
        while (isspace((chr = fgetc(stdin))) && (chr != '\n'));
        /* found the '\n', set the flag to exit the loop */
        if (chr == '\n')
            result = -1;
        else
        {
            /* not interesting put back this character for scanf to read it */
            ungetc(chr, stdin);
            /* save the result of scanf, that way you can validate input */
            result = scanf("%d", &a[i]);
            if (result == 1)
                i++;
        }
    }
    printf("read %d numbers\n", i);

    /* print the carachters, this will print in reverse obviously */
    while (--i >= 0)
        printf("%d\n", a[i]);


    return 0;
}