java中小数的加减乘除

public static void main(String[] args) {
double kk = 3.14;
kk += 0.37;
float ff = 3.14f;
ff += 0.37f;
System.out.println("double kk =" + kk);
System.out.println("float ff =" + ff);
}

输出结果：
double kk =3.5100000000000002
float ff =3.5100002

public static void main(String[] args) {
//小数加减乘除用BigDecimal
BigDecimal b1 = new BigDecimal("3.14");
BigDecimal b2 = new BigDecimal("0.37");
BigDecimal b3 = b1.add(b2);//
BigDecimal b4 = b1.subtract(b2);//
BigDecimal b5 = b1.multiply(b2);
System.out.println("3.14 + 0.37 = " + b3);
System.out.println("3.14 - 0.37 = " + b4);
System.out.println("3.14 * 0.37 = " + b5);
}

输出：
3.14 + 0.37 = 3.51
3.14 - 0.37 = 2.77
3.14 * 0.37 = 1.1618