c++ - 在打印之前检查 float 是否为偶数

Question

我有一个 float，其值如下:0.012447，我想重新调整 0.0 - 1.0 和用它来显示百分比，但我只想显示偶数值，例如... 12%、14%、16%、...

像这样:

float percent = ....
int value = percent * 100;

if(value == 12 || value == 14 || value == 16 .....){
 printf("Result: = %f\n", percent);
}

如果有一种不使用 percent * 10 和多个 ifs 的简单方法，我想要示例

Answer 1

作为@salcc 回答的补充，这可能接近您的要求；如果 value 是偶数，则有条件地打印它。

#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";
        }
    }
}

这种方法真正糟糕的是它可能会在输出中产生间隙。上面创建了这个输出:

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