Code to separate the whole part and decimal part - c++

Question

Screenshot of the outputs i got for the codeHow to code to separate the whole part and decimal part
I wrote this code but it gives different values at times. I don't know why?
#include <iostream>
using namespace std;
int main()
{
float f, a, b;
int x, y, c;
cout << "enter the float value" << endl; cin >> f;
x = (int)f; cout << "before " << x;
a = b = f;
c = 1;
while (b != int(a))
{
b = b * 10;
a = a * 10;
c = c * 10;
}
y = (f * c) - (x * c);
cout << "after " << y;
}
enter the float value
22.47
before 22 after 46
user#user:~/cpp$ ./a.out
enter the float value
2234.127
before 2234 after 126
user#user:~/cpp$ ./a.out
enter the float value
22.335
before 22 after 334
user#user:~/cpp$ ./a.out
enter the float value
222.88
before 222 after 88
these are a few values i tried.

Answer 1

How to code to separate the whole part and decimal part?
I assume that you want to only represent the floating value into non-decimals part and decimals part. In that case, take the user input as an std::string, and do as follows. I hope the comments will get you through the code:
(See live example)
#include <iostream>
#include <string>
#include <cstddef> // std::size_t
int main()
{
std::cout << "enter the float value\n";
std::string strInput; std::cin >> strInput; // take the user input as std::string
std::size_t pos{ 0 };
// find the position of charector decimal point('.') using std::string::find
pos = strInput.find(".", pos);
// if the decimal point is found in the user input: x = substring starting from 0 to pos of user input.
const std::string x = pos != std::string::npos ? strInput.substr(0, pos) : strInput;
// if the decimal point is found in the user input: y = substring starting from pos + 1 to end of user input.
const std::string y = pos != std::string::npos ? strInput.substr(pos + 1) : std::string{ "" };
std::cout << "before " << x << " after " << y << '\n';
return 0;
}
sample input:
enter the float value
0123.04560
Output:
before 0123 after 04560
PS: However, like in the example given above, having zero before the separated decimal parts(both 0123 and 04560) might be unwanted. In that case, use any of the standard functions to convert them back to integers or remove zeros from from the beginning using erase-remove idiom.