第1个回答 推荐于2018-03-11
float a = 1.435445678f;
double b = Double.parseDouble(String.valueOf(a)) ;//已四舍五入,精度保证
double b2 = a;//精度丢失!!!
System.out.println(b+" || "+b2);//1.4354457 || 1.4354456663131714
double x = 3.13145267878;
float y = (float) x;
float y2 = Float.parseFloat(String.valueOf(x));//未四舍五入,精度丢失!!!
System.out.println(y+" || "+y2);//3.1314526 || 3.1314526