java - 我在使用 .compareTo 函数时遇到问题

Question

这可能是一个非常简单的修复，但我不确定我做错了什么。我收到错误“无法解析方法 .compareTo(double)”

 public static void main(String[] args) throws IOException {


    Double angle = getUserDouble("Enter an angle in degrees:");
    Double userHeightInput = getUserDouble("Enter the height in meters:");

    final double G = 9.81; 
    final double DT = 0.01; 
    double theta = 45;
    double speed = 100.0; 
    double xPos = 0.0;
    double yPos = userHeightInput;
    double vX = speed *Math.cos(2.*Math.PI*theta/360);
    double vY = speed *Math.sin(2.*Math.PI*theta/360);
    double aY = -1.0;
    double aX = 0.0;
    double time = 0.0;

   FileWriter out = new FileWriter("output.csv");

   while (yPos.compareTo(0.0) > 0.0)
    {
        xPos = xPos + vX * DT;
        yPos = yPos + vY * DT;
        vX   = vY + aX * DT;
        vY   = vY + aY * DT;
    }
    String line = time + "," + xPos + "," + yPos + ","+ vX + "," +vY;
    out.write(line);
    out.close();
}

Answer 1

我认为发生此错误是因为必须在对象上调用 .compareTo()，但 double 是原始类型。尝试使用 >、<、== 等运算符进行简单比较。示例:

while (yPos > 0.0)

另一个选项是将 double 解析为 Double，以使其工作。然而，上面的选项似乎是更明显和值得推荐的选项。