将特定字符扫描到C中的数组中

Question

I am currently taking a basic C course and I was wondering why my code below doesn't run.

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

int main()
{ 
    char string[4];

    printf("Enter some text\n");
    scanf(" %c %c %c", &string[0], &string[1], &string[2]);

    printf("You Entered ");

    int i;
    for (i = 0; i < 4; i++){
        printf("%c",string[i]);
    }

    return 0;
}

Xcode said there is an errr with my scanf line.

I was hoping to type in "abcd" and expect a "You entered abcd";

Answer 1

This code should run (albeit with a bug). I suspect you need to configure the Xcode build options correctly.

As for the bug, you have an array of four chars, but you are only scanning for three. Add another %c and &string[3] to your scanf line.

Here's an ideone snippet showing the modified code in action

#include <stdio.h>

int main()
{ 
    char string[4];
    int i;

    printf("Enter some text\n");
    scanf("%c %c %c %c", &string[0], &string[1], &string[2], &string[3]);

    printf("You Entered ");

    for (i = 0; i < 4; i++){
        printf("%c", string[i]);
    }

    return 0;
}

This compiles just fine on the Mac command line (assuming the source is in "test.c")

$ cc -g -Wall -o test test.c 
./test
Enter some text
a b c d
You Entered abcd

Also note that this particular snippet requires only stdio.h ( man scanf and man printf will tell you which header to use).

Answer 2

How about executing this code?

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

int main()
{ 
    char strin[10];

    printf("Enter some text\n");
    scanf("%s", strin);

    printf("You Entered %s",strin);

    return 0;
}

The following code gives you :

Enter some text
abcd
You Entered abcd