如何用C#提取字符串中指定词汇并统计其数量？

嘿，我帮你调整了代码，刚好能实现提取匹配词汇并统计数量的需求，一起来看看：

解决方案代码 #

using System;
using System.Text.RegularExpressions;
using System.Linq;

public static class StringProcessor
{
    public static void ExtractAndCountMatches(string input)
    {
        // 定义要匹配的目标词汇，把多词短语放在前面避免被拆分匹配
        var targetWords = @"memory|buffer overflow|address space|stack overflow|call stack";
        // 查找所有匹配项，忽略大小写
        var matches = Regex.Matches(input, targetWords, RegexOptions.IgnoreCase);
        // 提取匹配内容、去重（忽略大小写）并整理成列表
        var uniqueMatches = matches.Cast<Match>()
                                   .Select(m => m.Value.Trim())
                                   .Distinct(StringComparer.OrdinalIgnoreCase)
                                   .ToList();
        // 拼接成逗号分隔的字符串
        var foundWords = string.Join(",", uniqueMatches);
        // 获取去重后的词汇数量
        var count = uniqueMatches.Count;
        
        // 输出结果
        Console.WriteLine($"Found: {foundWords}");
        Console.WriteLine($"Count: {count}");
    }
}

// 调用示例
var inputText = @"In software, a stack overflow occurs if the call stack pointer exceeds the stack bound. The call stack may consist of a limited amount of address space, often determined at the start of the program. The size of the call stack depends on many factors, including the programming language, machine architecture, multi-threading, and amount of available memory. When a program attempts to use more space than is available on the call stack (that is, when it attempts to access memory beyond the call stack's bounds, which is essentially a buffer overflow), the stack is said to overflow, typically resulting in a program crash.";

StringProcessor.ExtractAndCountMatches(inputText);

代码说明 #

• 用Regex.Matches替代原来的Replace，这样能捕获所有符合规则的匹配项，而不是直接替换掉
• 通过Distinct(StringComparer.OrdinalIgnoreCase)实现忽略大小写的去重，确保像Stack Overflow和stack overflow被识别为同一个词汇
• 最后把去重后的词汇拼接成你要的格式，数量直接取去重列表的长度即可

运行结果 #

Found: stack overflow,call stack,address space,memory,buffer overflow
Count:5

内容的提问来源于stack exchange，提问作者Nat