fscanf a number and store each digit in an array

Question

I have a file with a number like "100000". Is there a way to store each digit in an array? For example, I make an array[100] and I want array[0] = 1 , array[1] = 0 , array[2] = 0 and etc. I've looked it up but from what I gather, if I use a char array it takes it as a whole.

Answer 1

I probably would not use fscanf() for this:

while ((c = fgetc(fp)) != EOF && isdigit(c))
    array[i++] = c - '0';

If you must use fscanf() , then:

int i = 0;
int v;
while (fscanf(fp, "%1d", &v) == 1)
{
    assert(v >= 0 && v <= 9);
    array[i++] = v;
}

The 1 in the format string limits the integer to one digit. You must pass in an int * if you use %1d . If you have C99 support in your library, you could use:

int i = 0;
while (fscanf(fp, "%1hhd", &array[i++]) == 1)
    ;

The hh length modifier indicates that the pointer is a pointer to char (very short integer) rather than a pointer to int .

Answer 2

Is the number stored as literal '100000', or as its binary representation? if it's the literal '100000', just read it into a string, which is a char array already.

Answer 3

当您使用 fscanf 将输入读入 char 数组时，您可以遍历该数组并将 atoi 应用于每个元素并将输出（整数）放入 int 数组中。