如何使用特定字符将数组拆分为更小的数组？

Question

如何使用特定字符拆分字符串数组？此示例使用 '@':

string [] stringArray = new string [10];
stringArray[0] = "Hi there, this is page one" //goes into new arrayA
stringArray[1] = "Hi there, this is page two" //goes into new arrayA
stringArray[2] = "Hi there, this is page three" //goes into new arrayA
stringArray[3] = "@" //split
stringArray[4] = "New book, page one" //goes into new arrayB
stringArray[5] = "New book, page two" //goes into new arrayB

Answer 1

您可以编写一个使用 Skip 和 TakeWhile 的扩展方法。此解决方案是通用的，这意味着它适用于您提供的任何类型。请注意，对于引用类型，将进行值比较而不进行引用比较。

public static List<List<T>> Split<T>(this List<T> array, T seperator)
{
    var currentIndex = 0;
    var splitedList = new List<List<T>>();
    while (currentIndex < array.Count)
    {
        var part = array.Skip(currentIndex).TakeWhile(item => !item.Equals(seperator)).ToList();
        splitedList.Add(part);
        currentIndex += part.Count + 1;
    }
    return splitedList;
}

string[] stringArray = new string[6];
stringArray[0] = "Hi there, this is page one"; //goes into new arrayA
stringArray[1] = "Hi there, this is page two"; //goes into new arrayA
stringArray[2] = "Hi there, this is page three"; //goes into new arrayA
stringArray[3] = "@"; //split
stringArray[4] = "New book, page one"; //goes into new arrayB
stringArray[5] = "New book, page two"; //goes into new arrayB

var splittedValue = stringArray.ToList().Split("@");

我知道你有一个很大的列表，你想做一个像拆分这样的流，你可以使用 yield return。这样做的好处是，当读取列表中的下一项时，代码只会执行到下一个 yield return 语句。

public static IEnumerable<IList<T>> Split<T>(this IEnumerable<T> collection, T seperator)
{
    var items = new List<T>();
    foreach (var item in collection)
    {
        if (item.Equals(seperator))
        {
            yield return items;
            items = new List<T>();
        }
        else items.Add(item);
    }
    yield return items;
}

Answer 2

如果数组的大小不够大（数千项），您可以连接字符串，然后再拆分它们：

        string new_string = String.Join("#", stringArray);
        string[] combined_array = new_string.Split("@".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
        string[] new_array_1 = combined_array[0].Split("#".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);
        string[] new_array_2 = combined_array[1].Split("#".ToCharArray(), StringSplitOptions.RemoveEmptyEntries);

combined_array 中的项目数取决于“@”的数量。所以一般来说，您可以遍历 combined_array 并获得单独的数组。

Answer 3

应该这样做：

public IEnumerable<IEnumerable<T>> Split<T>(IEnumerable<T> input, T splitOn)
{
    var l = new List<T>();
    foreach (var item in input)
    {
        if(object.Equals(item, splitOn))
        {
            yield return l;
            l = new List<T>();
        }
        else
            l.Add(item);
    }
    yield return l;
}

Answer 4

另一种方法，使用带有 Skip、Take 和 yield return 的扩展方法进行延迟加载。在第二次编辑中，我让它使用泛型来拆分所有类型的 IEnumerables:

public static IEnumerable<IEnumerable<T>> SplitArray<T>(this IEnumerable<T> s,T splitItem)
{
    // First we get all the indexes where the string is found,
    // adding the last index of the array
    var indexes = s.Select((b, i) => b.Equals(splitItem) ? i : -1).Where(i => i != -1)
                   .Union(new int[] { s.Count() }).ToArray();

    int skip = 0; //variable to know where the next chunk starts
    foreach (int index in indexes)
    {
        IEnumerable<T> array = s.Skip(skip).Take(index - skip).ToArray();
        yield return array; //we return the chunk
        skip = index+1;
    }
}

用法：

foreach(var splitted in stringArray.SplitArray("@"))
{
     //splited is a string[]
}

如何使用特定字符将数组拆分为更小的数组？

How do I split an array into smaller arrays using a specific character?

c#

arrays

stringbuilder