替换列表中的字符串值 [英] Replace string values in list

问题描述

我有一个字符串集合，其中包含"goalXXvalue，goalXXLength，TestXX"之类的值.这是一个列表(字符串) 我以为我可以遍历每个项目并用下面的方法替换我尝试过的XX值，但是这些值不会改变.我要去哪里错了? 谢谢

I have a collection of strings which contain values like "goalXXvalue,goalXXLength,TestXX". It is a List(of String) I thought I would be able to loop through each item and replace the XX value which I've tried with the method below but the values don't change. Where am I going wrong? Thanks

metricList.ForEach(Function(n) n.Replace("XX", "1"))

metricList.ForEach(Function(n) n.Replace("XX", "1"))

推荐答案

您在这里遇到一些问题:

You have a few issues here:

• 首先，字符串是不可变的，因此，当您调用.Replace时，您将返回一个新字符串.调用n.Replace不会修改n.
• 在匿名函数中分配给n不会影响列表中的值.
• 无论如何，枚举时都不能更改集合的内容，因为它将使枚举无效.

• first, strings are immutable, so when you call .Replace you return a new string. Calling n.Replace doesn't modify n.
• assigning to n in your anonymous function won't affect the value that's in your list.
• regardless of the above, you can't change the content of your collection while enumerating it, because it'll invalidate the enumeration.

由于似乎您要更改列表中的每个字符串，因此似乎无需尝试就地修改集合.因此，简洁的解决方案是使用Linq创建一个新列表:

Since it seems you're changing every string in your list, it seems unnecessary to try to modify the collection in-place. Therefore, the succint solution would be to use Linq would to create a new list:

var newList = metricList.Select(s => s.Replace("XX", "1")).ToList();

这篇关于替换列表中的字符串值的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！