有没有更优雅的方法来添加可为null的int? [英] Is there a more elegant way to add nullable ints?
问题描述
我需要添加大量可为null的int类型的变量.我使用空合并运算符将其降低到每行一个变量,但是我觉得有一种更简洁的方法可以做到这一点,例如我不能以某种方式将这些语句链接在一起,我之前在其他代码中已经看到过.
I need to add numerous variables of type nullable int. I used the null coalescing operator to get it down to one variable per line, but I have a feeling there is a more concise way to do this, e.g. can't I chain these statements together somehow, I've seen that before in other code.
using System;
namespace TestNullInts
{
class Program
{
static void Main(string[] args)
{
int? sum1 = 1;
int? sum2 = null;
int? sum3 = 3;
//int total = sum1 + sum2 + sum3;
//int total = sum1.Value + sum2.Value + sum3.Value;
int total = 0;
total = total + sum1 ?? total;
total = total + sum2 ?? total;
total = total + sum3 ?? total;
Console.WriteLine(total);
Console.ReadLine();
}
}
}
推荐答案
var nums = new int?[] {1, null, 3};
var total = nums.Sum();
这依赖于 IEnumerable<Nullable<Int32>>
重载 href ="http://msdn.microsoft.com/zh-cn/library/bb345537.aspx" rel ="noreferrer"> Enumerable.Sum
方法,其作用与您期望的一样.
This relies on the IEnumerable<Nullable<Int32>>
overload of the Enumerable.Sum
Method, which behaves as you would expect.
如果默认值不等于零,则可以执行以下操作:
If you have a default-value that is not equal to zero, you can do:
var total = nums.Sum(i => i.GetValueOrDefault(myDefaultValue));
或速记:
var total = nums.Sum(i => i ?? myDefaultValue);
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