如何在C++中通过单词知道每个字符串的长度

Question

想知道如何拆分每个字符串并得到单词数。但是我一直收到错误 'Split': is not a member of 'System::Array' with a split or piece in the third line.

String^ originalString = textBox1->Text;//original text string
cli::array<String^>^ piece= originalString->Split('.');//text is being split into sentences    
cli::array<String^>^ sentence = piece->Split(' ');// text is being split into words, also I get error here
for (int i = 0; i < sentence->Length; ++i) {
datagridview1->Rows[i]->Cells[2]->Value = i;}

Answer 1

您可以先获取句子，它们是由“.”分隔的词组。字符，然后得到每个句子的个单词，由一个空格字符分隔。

using namespace System;
using namespace System::Collections::Generic;
using namespace System::Diagnostics;

String^ originalString = "This is a chord. This is another. This is a third. Now form a band.";

// This array contains the sentences, which are separated by '.'
array<String^>^ sentences = originalString->Split(
    gcnew array<String^> { "." },
    StringSplitOptions::RemoveEmptyEntries);

Debug::Assert(sentences->Length == 4);

// This list contains individual words for all sentences.
List<String^>^ words = gcnew List<String^>();
for each(String^ sentence in sentences) {
    words->AddRange(sentence->Split(
        gcnew array<String^> { " " },
        StringSplitOptions::RemoveEmptyEntries));
}

Debug::Assert(words->Count == 15);

for each(String^ word in words) {
    Console::WriteLine(word);
}

但是如果您唯一感兴趣的是单个单词，您可以使用 LINQ 在单个表达式中获取它们：

using namespace System;
using namespace System::Collections::Generic;
using namespace System::Diagnostics;
using namespace System::Linq;

System::String^ StripDot(System::String^ input) {
    return input->Replace(".", "");
}

void Test()
{
    String^ originalString = "This is a chord. This is another. This is a third. Now form a band.";

    IEnumerable<String^>^ words = Enumerable::Select<String^,String^>(
        originalString->Split(
            gcnew array<String^> { " " },
            StringSplitOptions::RemoveEmptyEntries),
        gcnew Func<String^,String^>(StripDot));

    Debug::Assert(Enumerable::Count(words) == 15);

    for each(String^ word in words) {
        Console::WriteLine(word);
    }
}

Answer 2

我认为你能做的最简单的事情就是使用 Regex:

String^ text = "This is a chord. This is another. This is a third. Now form a band.";

int wordCount = Regex::Matches(text, "\w+")->Count; // = 15

哪里

\w stands for "word character". It always matches the ASCII characters [A-Za-z0-9_]. Notice the inclusion of the underscore and digits.

Shorthand Character Classes

更新为：

but I need a number of words in each sentence

在这种情况下，这应该适合你：

using namespace System;
using namespace System::Collections::Generic;
using namespace System::Diagnostics;
using namespace System::Linq;
using namespace System::Text::RegularExpressions;

static int CountWords(String^ text) 
{
    return Regex::Matches(text, "\w+")->Count;
}

int main(array<System::String ^> ^args)
{
    String^ text = "This is a chord. This is another. This is a third. Now form a band.";

    // split sentences
    IEnumerable<String^>^ sentences = Regex::Split(text, "[.!?](?!$)"); 
    List<int>^ wordCounts = Enumerable::ToList(
        // count words for each sentence
        Enumerable::Select<String^, int>(sentences, gcnew Func<String^, int>(&CountWords)));
}

其中：

[.!?] 匹配这三个句子结尾中的任何一个，因此将文本拆分到那里
(?!$) 它是一个否定前瞻 ?!，它确保以 .!? 结尾的最后一句话不在文本 $ 的末尾，这将导致空字符串

如何在C++中通过单词知道每个字符串的长度

How to know each string length by words in C++

c++-cli