分割两位数字

Question

I try to split any number of two digits and get result in two different variables. I had a problem with a specific number: 23 .

int root = 23;
float div = (float)root/10.0; // div = 23.0/10.0 = 2.3

int left = (int)div; // left = 2
int right = ((float)div - (float)left) * 10.0; // right = (2.3 - 2) * 10.0 = 0.3 * 10.0 = 3

printf("%d", right); // 2, why ?

There is a lot of float-to-int operations and I got some troubles with the final result. Have I miss or didn't catch something ?

Answer 1

Since 0.3 may not be represented exactly in binary, you end up with 2.9999… that became 2 when converted to an int .

Instead:

int root = 23;
int left = root / 10;
int right = root % 10;