numbers after the floating point

[Bleedz129]

if we have a decimal number like c=3.46

And i want to set two number, a and b

now a= static_type<int>(c); so a=3;
and i want b= 46

which is the two numbers after the decimal
how can I do that ? how can I set b = 46 ?

P.S: i do not know what c equals to. now it's two number after the floating point but it might be more or less

[giblit]

So are you saying you know a and b but not c? This you would mean you would have to divide b by 10^digits and add it to a.

[Bleedz129]

giblit

i do not know anything. c is being set by the user.

[wildblue]

You have 3.46 and the integer part already (3) - so the difference between those is the fractional amount. But you want to get rid of the decimal point?

[giblit]

If it is set by the user you will know what it is after they give it a value. This would mean that you will want to find a a = static_cast<int>(c); then subtract a from c and multiply by 10 until there are no more decimal digits.

You could also simply use stringstreams.

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#include <iostream> #include <sstream> #include <string> int main() { double input; std::cout << "Please enter a floating-point number: "; std::cin >> input; std::stringstream ss; ss << input; int characteristic, mantissa; char decimal; ss >> characteristic >> decimal >> mantissa; std::cout << "Characteristic: " << characteristic << std::endl; std::cout << "Mantissa: " << mantissa << std::endl; return 0; }

Please enter a floating-point number: 12.414 Characteristic: 12 Mantissa: 414

http://coliru.stacked-crooked.com/a/18e61d93a916d8c8

Though keep in mind if you have a large floating-point number you are going to want to include iomanip and then use std::setprecision

[Bleedz129]

How do you multiply by 10 until there is no more decimal point ? we don't know how many times we have to multiply

let me make my question simpler with this program

cout << "enter length of the road, and enter how fast you are going " << endl;
cin >> length >> mph;

time = length/mph;
hours = static_cast<int>(time);
minutes = (the numbers after the decimal point) * 60;
seconds = (the numbers after the decimal point of minutes) * 60

so how do we get those numbers after the decimal point ? I know it involves modulus

[giblit]

Getting the mantissa would be very hard with modulus.

How do you multiply by 10 until there is no more decimal point ?

If you keep multiplying by 10 eventually the mantissa will be 0. Basically something like:

a == 0.12345
0.12345 - 0 = 0.12345, the mantissa is not 0

a * 10 == 1.2345
1.2345 - 1 = 0.2345, the mantissa is not 0

a * 100 == 12.345
12.345 - 12 = 0.345, the mantissa is not 0

a * 1000 == 123.45
123.45 - 123 = 0.45, the mantissa is not 0

a * 10000 == 1234.5
1234.5 - 1234 = 0.5, the mantissa is not 0

a * 100000 = 12345.0
12345 - 12345 = 0.0, the mantissa is 0

Keep in mind that checking if the mantissa is equal to 0 you will need to use a very small threshold something like double threshold = 0.00000000000001;

[Bleedz129]

got the logic thanks