Recently, I used double type addition in my work, and found that there was a problem with the accuracy of the result.
The answer is obtained after verification by Baidu, which is hereby recorded.
When adding data of double type, use the + sign directly, and the result will have a precision error
So you need to use the BigDecimal function for operation
double v1 = 4.5; double v2 = 4.55; BigDecimal b1 = new BigDecimal(Double.toString(v1)); BigDecimal b2 = new BigDecimal(Double.toString(v2)); double sum= b1.add(b2).doubleValue();