本文是小编为大家收集整理的关于枚举.重复有一些内存问题吗?的处理/解决方法，可以参考本文帮助大家快速定位并解决问题，中文翻译不准确的可切换到English标签页查看源文。
问题描述
我将一个数组初始化为
Double[][] myarr = Enumerable.Repeat(new double[12], 13).ToArray();
然后在循环中我正在增加
之类的值myarr[0][0]++;
这会导致所有值，例如Myarr [1] [0]，Myarr [2] [0]，Myarr [3] [0] ..... Myarr [12] [0]递增一个.
使用for循环时不会发生这个问题(0-12)我正在初始化
myarr[i] = new double[12];
为什么这样?
推荐答案
其他答案解释了问题.解决方案是在每个迭代中创建一个新数组，例如
double[][] myarr = Enumerable.Range(0, 13)
.Select(ignored => new double[12])
.ToArray();
其他推荐答案
with new double[12]您正在创建对双打数组的引用，然后重复参考 12次，因此Myarr [0..n]将参考一个内存区域.
您可以使用效率方法来解决问题
static T[][] CreateArray<T>(int rows, int cols)
{
T[][] array = new T[rows][];
for (int i = 0; i < array.GetLength(0); i++)
array[i] = new T[cols];
return array;
}
或使用自定义重复方法调用操作的每个步骤:
public static IEnumerable<TResult> RepeatAction<TResult>(Action<TResult> elementAction, int count)
{
for (int i = 0; i < count; i++)
{
yield return elementAction();
}
yield break;
}
usage
RepeatAction(()=>new double[12], 12);
其他推荐答案
这是因为new double[12]在内存中创建一个单个数组对象-Enumobles.Repeat只是为您提供对该数组的多个引用.
问题描述
I initialized an Array as
Double[][] myarr = Enumerable.Repeat(new double[12], 13).ToArray();
Then in a loop i am incrementing values like
myarr[0][0]++;
This causes all values like myarr[1][0], myarr[2][0], myarr[3][0] ..... myarr[12][0] to increment by one.
This problem is not occurring when using a for loop (0-12) i am initializing like
myarr[i] = new double[12];
Why is this so?
推荐答案
Other answers have explained the problem. The solution is to create a new array on each iteration, e.g.
double[][] myarr = Enumerable.Range(0, 13)
.Select(ignored => new double[12])
.ToArray();
其他推荐答案
With new double[12] you are creating reference to array of doubles, and then you repeate the reference 12 times, so myarr[0..n] will have reference to one memory region.
You can use the folowing method to resolve thw issue
static T[][] CreateArray<T>(int rows, int cols)
{
T[][] array = new T[rows][];
for (int i = 0; i < array.GetLength(0); i++)
array[i] = new T[cols];
return array;
}
Or with custom Repeat method which calls action every step:
public static IEnumerable<TResult> RepeatAction<TResult>(Action<TResult> elementAction, int count)
{
for (int i = 0; i < count; i++)
{
yield return elementAction();
}
yield break;
}
usage
RepeatAction(()=>new double[12], 12);
其他推荐答案
It's because new double[12] creates a single array object in memory - Enumerable.Repeat is simply providing you with multiple references to that array.
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