如何测试double是否为整数 - How to test if a double is an integer

问题：

Is it possible to do this?是否有可能做到这一点？

double variable;
variable = 5;
/* the below should return true, since 5 is an int. 
if variable were to equal 5.7, then it would return false. */
if(variable == int) {
    //do stuff
}

I know the code probably doesn't go anything like that, but how does it go?我知道代码可能不会去这样的事情，但它是如何走？

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解决方案：

参考一： https://en.stackoom.com/question/fX3Q
参考二： https://stackoom.com/question/fX3Q