bigdecimal

不论是float 还是double都是浮点数，而计算机是二进制的，浮点数会失去一定的精确度。Java在java.math包中提供的API类BigDecimal，用来对超过16位有效位的数进行精确的运算。BigDecimal所创建的是对象，我们不能使用传统的+、-、*、/等算术运算符直接对其对象进行数学运算，而必须调用其相对应的方法。方法中的参数也必须是BigDecimal的对象。构造器是类的特殊方法，专门用来创建对象，特别是带有参数的对象。 下面是个例子： http://yayihouse.com/yayishuwu/chapter/2081 来源： https://blog.csdn.net/qq_37599827/article/details/98884664

I want to do some simple sums with some currency values expressed in BigDecimal type. BigDecimal test = new BigDecimal(0); System.out.println(test); test.add(new BigDecimal(30)); System.out.println(test); test.add(new BigDecimal(45)); System.out.println(test); Obviously I do not understand well the BigDecimal arithmetics, see output behind. Test 0 0 0 Can anyone help me out? Vincent Ramdhanie The BigDecimal is immutable so you need to do this: BigDecimal result = test.add(new BigDecimal(30)); System.out.println(result); It looks like from the Java docs here that add returns a new BigDecimal:

I'm looking for a good arbitrary precision math library in C or C++. Could you please give me some advices / suggestions? The primary requirements: It MUST handle arbitrarily big integers (my primary interest is on integers). In case that you don't know what the word arbitrarily big means, imagine something like 100000! (the factorial of 100000). The precision MUST NOT NEED to be specified during library initialization / object creation. The precision should ONLY be constrained by the available resources of the system. It SHOULD utilize the full power of the platform, and should handle "small"