检查arraylist元素等于数组 [英] check arraylist element equals an array

问题描述

我正在尝试测试元素是否等于数组。但是，即使array == arraylist [element]，重复值仍然设置为false。



这是我的代码：



bool重复= false;

foreach（arraylist中的var元素）

{

if（array.Equals） （元素））

重复=真;

}

返回重复;

I am trying to test whether an element equals an array. However, even if array==arraylist[element] the value of repetitive is still set to false.

Here is my code:

bool repetitive = false;
foreach(var element in arraylist)
{
if (array.Equals(element))
repetitive = true;
}
return repetitive;

推荐答案

在新开发中永远不要使用 ArrayList 。早在.NET v.2.0中，当实现泛型时，所有非泛型类都被淘汰了。他们消除了不必要的潜在危险元素类铸造使用泛型 System.Collections.Generic.List<> 和其他通用集合。



你的代码没有你可以将一些元素与整个数组进行比较（如果你的数组对象是数组;它是未声明的），它总是为假。此外， System.Equals 不适合直接通话;它的目的是非常不同的。



完全不清楚你想要实现什么（如果它甚至没有任何意义;因为它甚至不会编译因为数组未声明和定义），但您需要的最接近的方法是任何或此处描述的所有 扩展方法：

http://msdn.microsoft.com/en-us/library/6sh2ey19%28v=vs.110%29.aspx [<一个href =http://msdn.microsoft.com/en-us/library/6sh2ey19%28v=vs.110%29.aspxtarget =_ blanktitle =New Window> ^ ]。

-SA

Never use ArrayList in new development. All non-generic classes were rendered obsolete as early as of .NET v.2.0, when generics were implemented. They eliminate unwanted potentially dangerous element type casting. Use generic System.Collections.Generic.List<> and other generic collection.

Your code makes no sense at all, you compare some element with the whole array (if your array object is array; it is undeclared), which always be false. Moreover, System.Equals is not intended for direct call; its purpose is very different.

It's totally unclear what you are trying to achieve (if it even makes any sense at all; as is, it won't even compile because array is not declared and defined), but the closest approach you would need is this one of Any or All extension methods described here:
http://msdn.microsoft.com/en-us/library/6sh2ey19%28v=vs.110%29.aspx[^].

—SA

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