Checking if a float is an even number before printing it - c++

Question

I have a float that has a value like this: 0.012447, I want to rescale the value I have between 0.0 - 1.0 and use it to display a percentage, but I would like to only display even values, like ... 12%, 14%, 16%, ...
Something like this:
float percent = ....
int value = percent * 100;
if(value == 12 || value == 14 || value == 16 .....){
printf("Result: = %f\n", percent);
}
If there is an easy way to do it without using the percent * 10 and multiple ifs i would like examples

Answer 1

As a complement to #salcc's answer, this is probably close to what you ask for; conditional printing of value if it's even.
#include <cmath>
#include <iostream>
int main() {
for(float percent = 0.f; percent <= 1.f; percent += 1.f / 47.f) {
int value = static_cast<int>(std::round(percent * 100.f));
if(value % 2 == 0) { // Is it even? If so, print it.
std::cout << "Result: = " << value << "\n";
}
}
}
What's really bad with this approach is that it may create gaps in the output. The above creates this output:
Result: = 0
Result: = 2
Result: = 4
Result: = 6
Result: = 26
Result: = 28
Result: = 30
Result: = 32
Result: = 34
Result: = 36
Result: = 38
Result: = 40
Result: = 60
Result: = 62
Result: = 64
Result: = 66
Result: = 68
Result: = 70
Result: = 72
Result: = 74
Result: = 94
Result: = 96
Result: = 98
Result: = 100

Answer 2

To round to the nearest even number you can divide the number by two, round the result, and then multiply it by two. You can do that and convert it to a percentage by just doing:
printf("Result: %g%%\n", round(percent * 100 / 2.0) * 2);
To use the round() function, you have to put #include <cmath> at the top of the file.
Demo:
float percent = 0.129;
printf("Result: %g%%\n", round(percent * 100 / 2.0) * 2);
Output:
Result: 12%