浮点数精度问题

    public static void main(String[] args) {
        double d = 11.4;
        int i = 13;
        double a = d*i;
        System.out.println("反例："+a);
        
        BigDecimal num12 = new BigDecimal(d);
        BigDecimal num22 = new BigDecimal(i);
        BigDecimal result32 = num12.multiply(num22);
        System.out.println("反例："+result32);
        
        BigDecimal num13 = new BigDecimal(Double.toString(d));
        BigDecimal num23 = new BigDecimal(Double.toString(i));
        BigDecimal result33 = num13.multiply(num23);
        System.out.println("正例："+result33);
        
        BigDecimal num14 = BigDecimal.valueOf(d);
        BigDecimal num24 = BigDecimal.valueOf(i);
        BigDecimal result34 = num14.multiply(num24);
        System.out.println("正例："+result34);
    }