C：如何使用scanf存储未知数量的输入，以便将输入的每个单词存储在不同的变量中？

Question

So far i have:

    char r[4][10];

    printf("Enter an option: \n");
    scanf("%s %s %s %s %s", r[0],r[1],r[2], r[3], r[4]);
    printf("%s %s %s %s %s\n", r[0], r[1], r[2], r[3], r[4]);

This works as long as 5 inputs are given. Right now if you type less then 5 inputs and hit enter the program continues to ask for input until it has all 5 values but I want the scanf to stop and the program to continue if less then 5 inputs are entered.

Answer 1

You'll do best to read a line with fgets() and parse it with sscanf() . If there will be no more than 5 words on a line:

char r[5][10];
char line[4096];

printf("Enter an option: \n");
if (fgets(line, sizeof(line), stdin) != 0)
{
    int num = sscanf(line, "%9s %9s %9s %9s %9s", r[0],r[1],r[2], r[3], r[4]);
    for (int i = num; i < 5; i++)
        r[i][0] = '\0';
    printf("%s %s %s %s %s\n", r[0], r[1], r[2], r[3], r[4]);
}

Note that you only had r[4][10] but were using subscript 4 — bad move.

A better way to handle it would be a loop that scans over the line, reading a word at a time until there is no more space in the array or no more words in the line. It's a little trickier, though.