可能重复: C编程部门
可能我的问题很简单愚蠢。 我想存储一个部门的值,特别是 1 / x 其中 x 是一个整数值。
probably my question is very simple and stupid. I would like to store the value of a division, in particular 1 / x where x is a integer value.
int x = 17; double result = 1/x;我尝试这样做,但我总是得到 0.000000 ... 我尝试输入固定在x中的值,例如 1/17 ,但总是得到相同的值..什么是错误?
I try to do it but I always get 0.000000 ... I try to enter a value fixed in x, for example 1/17 but always get the same value .. what's Wrong?
推荐答案您正在进行整数除法。
尝试以下操作,它将按预期工作:
Try the following and it will work as expected:
int x = 17; double result = 1.0 / x;表达式中 1 的类型你以上是 int ,而 x 的类型是int。当你执行 int / int ,你会得到一个int回来。您需要至少有一种涉及浮点的类型( float 或 double ),以便浮点除法发生。
The type of the 1 in the expression you have above is int, and the type of x is int. When you do int / int, you get an int back. You need at least one of the types involved to be floating point (float or double) in order for floating point division to occur.
与数学不同,C ++中的划分可以指截断的整数除法(你所做的)还是浮点除法(在我的例子中我做了什么)。小心这个!
Unlike in Mathematics, division in C++ can either refer to truncated integer division (what you did) or floating point division (what I did in my example). Be careful of this!
在我的例子中,我们明确地说明了 double / int - >双重。
In my example, explicitly what we have is double / int -> double.
更多推荐
整数除法始终为零
发布评论