如何从C＃中的数组中删除一个元素(How to delete an element from an array in C#)

如何从C＃中的数组中删除一个元素(How to delete an element from an array in C#)

让我说我有这个数组，

int[] numbers = {1, 3, 4, 9, 2};

如何通过“名称”删除元素？ 可以说4号吗？

甚至ArrayList没有帮助删除？

string strNumbers = " 1, 3, 4, 9, 2"; ArrayList numbers = new ArrayList(strNumbers.Split(new char[] { ',' })); numbers.RemoveAt(numbers.IndexOf(4)); foreach (var n in numbers) { Response.Write(n); }

Lets say I have this array,

int[] numbers = {1, 3, 4, 9, 2};

How can I delete an element by "name"? , lets say number 4?

Even ArrayList didn't help to delete?

string strNumbers = " 1, 3, 4, 9, 2"; ArrayList numbers = new ArrayList(strNumbers.Split(new char[] { ',' })); numbers.RemoveAt(numbers.IndexOf(4)); foreach (var n in numbers) { Response.Write(n); }

最满意答案

如果要删除4的所有实例，而不需要知道索引：

LINQ：（. NET Framework 3.5）

int[] numbers = { 1, 3, 4, 9, 2 }; int numToRemove = 4; numbers = numbers.Where(val => val != numToRemove).ToArray();

非LINQ：（. NET Framework 2.0）

static bool isNotFour(int n) { return n != 4; } int[] numbers = { 1, 3, 4, 9, 2 }; numbers = Array.FindAll(numbers, isNotFour).ToArray();

如果要仅删除第一个实例：

LINQ：（. NET Framework 3.5）

int[] numbers = { 1, 3, 4, 9, 2, 4 }; int numToRemove = 4; int numIndex = Array.IndexOf(numbers, numToRemove); numbers = numbers.Where((val, idx) => idx != numIndex).ToArray();

非LINQ：（. NET Framework 2.0）

int[] numbers = { 1, 3, 4, 9, 2, 4 }; int numToRemove = 4; int numIdx = Array.IndexOf(numbers, numToRemove); List<int> tmp = new List<int>(numbers); tmp.RemoveAt(numIdx); numbers = tmp.ToArray();

编辑：如果你还没有想出来，就像Malfist指出的那样，你需要定位.NET Framework 3.5，以使LINQ代码示例工作。 如果您要定位2.0，则需要参考非LINQ示例。

If you want to remove all instances of 4 without needing to know the index:

LINQ: (.NET Framework 3.5)

int[] numbers = { 1, 3, 4, 9, 2 }; int numToRemove = 4; numbers = numbers.Where(val => val != numToRemove).ToArray();

Non-LINQ: (.NET Framework 2.0)

static bool isNotFour(int n) { return n != 4; } int[] numbers = { 1, 3, 4, 9, 2 }; numbers = Array.FindAll(numbers, isNotFour).ToArray();

If you want to remove just the first instance:

LINQ: (.NET Framework 3.5)

int[] numbers = { 1, 3, 4, 9, 2, 4 }; int numToRemove = 4; int numIndex = Array.IndexOf(numbers, numToRemove); numbers = numbers.Where((val, idx) => idx != numIndex).ToArray();

Non-LINQ: (.NET Framework 2.0)

int[] numbers = { 1, 3, 4, 9, 2, 4 }; int numToRemove = 4; int numIdx = Array.IndexOf(numbers, numToRemove); List<int> tmp = new List<int>(numbers); tmp.RemoveAt(numIdx); numbers = tmp.ToArray();

Edit: Just in case you hadn't already figured it out, as Malfist pointed out, you need to be targetting the .NET Framework 3.5 in order for the LINQ code examples to work. If you're targetting 2.0 you need to reference the Non-LINQ examples.