在一行代码中使用LINQ将字符串[]转换为int[]

I have an array of integers in string form:

我有一个字符串形式的整数数组:

var arr = new string[] { "1", "2", "3", "4" };

I need to an array of 'real' integers to push it further:

我需要一个'real' integers的数组来进一步推动它:

void Foo(int[] arr) { .. }

I tried to cast int and it of course failed:

我试着投射int，当然失败了:

Foo(arr.Cast<int>.ToArray());

I can do next:

我可以做下一个:

var list = new List<int>(arr.Length);
arr.ForEach(i => list.Add(Int32.Parse(i))); // maybe Convert.ToInt32() is better?
Foo(list.ToArray());

或

var list = new List<int>(arr.Length);
arr.ForEach(i =>
{
   int j;
   if (Int32.TryParse(i, out j)) // TryParse is faster, yeah
   {
      list.Add(j);
   }
 }
 Foo(list.ToArray());

but both looks ugly.

但看起来丑陋。

Is there any other ways to complete the task?

完成这项任务还有其他方法吗?

6 个解决方案

#1

472

Given an array you can use the Array.ConvertAll method:

给定一个数组，您可以使用该数组。ConvertAll方法:

int[] myInts = Array.ConvertAll(arr, s => int.Parse(s));

Thanks to Marc Gravell for pointing out that the lambda can be omitted, yielding a shorter version shown below:

感谢Marc Gravell指出lambda可以省略，从而产生一个更短的版本，如下所示:

int[] myInts = Array.ConvertAll(arr, int.Parse);

A LINQ solution is similar, except you would need the extra ToArray call to get an array:

LINQ解决方案是类似的，除非您需要额外的ToArray调用来获得一个数组:

int[] myInts = arr.Select(int.Parse).ToArray();

#2

EDIT: to convert to array

编辑:转换为数组

int[] asIntegers = arr.Select(s => int.Parse(s)).ToArray();

This should do the trick:

这应该可以做到:

var asIntegers = arr.Select(s => int.Parse(s));

#3

To avoid exceptions with .Parse, here are some .TryParse alternatives.

为了避免. parse的异常，这里有一些. tryparse替代方法。

To use only the elements that can be parsed:

只使用可分析的元素:

string[] arr = { null, " ", " 1 ", " 002 ", "3.0" };
int i = 0; 
var a = (from s in arr where int.TryParse(s, out i) select i).ToArray();  // a = { 1, 2 }

或

var a = arr.SelectMany(s => int.TryParse(s, out i) ? new[] { i } : new int[0]).ToArray();

Alternatives using 0 for the elements that can't be parsed:

对不能解析的元素使用0的替代方法:

int i; 
var a = Array.ConvertAll(arr, s => int.TryParse(s, out i) ? i : 0); //a = { 0, 0, 1, 2, 0 }

或

var a = arr.Select((s, i) => int.TryParse(s, out i) ? i : 0).ToArray();

#4

you can simply cast a string array to int array by:

您可以通过以下方法将字符串数组转换为int数组:

var converted = arr.Select(int.Parse)

#5

var asIntegers = arr.Select(s => int.Parse(s)).ToArray();

Have to make sure you are not getting an IEnumerable<int> as a return

必须确保您没有得到IEnumerable 作为返回

#6

var list = arr.Select(i => Int32.Parse(i));

#1

472