创建未定义长度的 c# 对象数组？
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Create c# object array of undefined length?
提问by Lyndal
I would like to create an object array in C# of undefined length and then populate the array in a loop like so...
我想在 C# 中创建一个未定义长度的对象数组，然后像这样在循环中填充数组......
string[] splitWords = message.Split(new Char[] { ' ' });
Word[] words = new Word[];
int wordcount = 0;
foreach (string word in splitWords)
{
if (word == "") continue;
words[wordcount] = new Word(word);
wordcount++;
}
However, I get the error... "Array creation must have array size or array initializer"
但是，我收到错误...“数组创建必须具有数组大小或数组初始值设定项”
I'm doing a lot more logic in the foreach loop that I've left out for brevity.
为了简洁起见，我在 foreach 循环中做了更多的逻辑。
采纳答案by jasonh
What you want to do is create:
您要做的是创建：
List<Word> words = new List<Word>();
and then:
进而：
words.Add(new Word(word));
And finally when the loop is done if you need an array:
最后当循环完成时，如果你需要一个数组：
words.ToArray();
回答by statenjason
You can't create an array of undefined length. This is where you'd use a generic List.
您不能创建未定义长度的数组。这是您使用通用列表的地方。
List<Word> words = new List<Word>();
回答by JaredPar
If you're using C# 3.5, you can just do the following.
如果您使用的是 C# 3.5，则只需执行以下操作。
var words = message
.Split(new char[]{' '})
.Where(x => x != "")
.Select(x => new Word(x))
.ToArray();
回答by Lyndal
I solved it by using an ArrayList and then casting it to the object array after iterating...
我通过使用 ArrayList 解决了它，然后在迭代后将其转换为对象数组...
string[] splitWords = message.Split(new Char[] {' '});
ArrayList wordList = new ArrayList();
int wordcount = 0;
foreach (string word in splitWords)
{
if (word == "") continue;
Word newWord = new Word(word);
wordList.Add(newWord);
wordcount++;
}
Word[] words = (Word[])wordList.ToArray(typeof(Word));
I've heard the whole "create question/answer just to document it for others" is acceptable. Plus I'd like to hear if there are better suggestions. Thanks.
我听说整个“创建问题/答案只是为了为他人记录”是可以接受的。另外，我想听听是否有更好的建议。谢谢。
回答by David.Chu.ca
Actually you may use list to populate your words first and then convert it easily to array like this:
实际上，您可以先使用 list 填充单词，然后将其轻松转换为数组，如下所示：
string[] splitWords = message.Split(new Char[] { ' ' });
List<Word> words = new List<Word>();
int wordcount = 0;
foreach (string word in splitWords)
{
if (word == "") continue;
words.add(new Word(word));
//wordcount++;
}
wordcount = words.count;
return words.ToArray();
回答by Talljoe
A friendly note, you can pass option to split to ignore empty entries. Assuming no other logic to prune out entries you can preinitialize your array like so:
友情提示，您可以通过选项 split 来忽略空条目。假设没有其他逻辑来修剪条目，您可以像这样预初始化数组：
string[] splitWords = message.Split(new Char[] {' '},
StringSplitOptions.RemoveEmptyEntries);
Word[] words = new Word[splitWords.Length];
回答by Aaaaa
I'm wondering why can't we just use a string variable (say x), initialize it and retrieve comma separated data in it and later use string[]variable (say y[]) and initialize it equal to x.Split(',')without having to initialize a blank array like follows:
我想知道为什么我们不能只使用字符串变量（比如x），初始化它并检索其中的逗号分隔数据，然后使用string[]变量（比如y[]）并将其初始化为等于x.Split(',')而不必初始化一个空数组，如下所示：
string x = string.Empty;
string msg = "hi,how,r,u,xyz";
void Page_Load(object sender, EventArgs e)
x = msg;
string[] y = msg.Split(',');
I think this should work as needed but I didn't try running this so I am not sure. If someone thinks that my solution is wrong, please correct me.
我认为这应该根据需要工作，但我没有尝试运行它，所以我不确定。如果有人认为我的解决方案是错误的，请纠正我。
