Question

请考虑以下示例。

string s = "The man is old. Them is not bad.";

如果我使用

s = s.Replace("The", "@@");

然后它返回"@@ man is old. @@m is not bad."
但我希望输出为"@@ man is old. Them is not bad."

我该怎么做？

Answer 1

以下是你如何使用正则表达式来处理任何单词边界：

Regex r = new Regex(@"\bThe\b");
s = r.Replace(s, "@@");

Answer 2

我在上面做了一个评论，询问为什么标题被更改为假设使用正则表达式。

我个人尝试不使用正则表达式，因为它很慢。 Regex非常适合复杂的字符串模式，但是如果字符串替换很简单并且你需要一些性能，我会试着找到一种不使用Regex的方法。

一起测试。使用Regex和字符串方法运行一百万次替换。

正则表达 26.5秒完成，字符串方法 8秒完成。

        //Using Regex. 
        Regex r = new Regex(@"\b[Tt]he\b");

        System.Diagnostics.Stopwatch stp = System.Diagnostics.Stopwatch.StartNew();

        for (int i = 0; i < 1000000; i++)
        {
            string str = "The man is old. The is the Good. Them is the bad.";
            str = r.Replace(str, "@@");
        }

        stp.Stop();
        Console.WriteLine(stp.Elapsed);

        //Using String Methods.
        stp = System.Diagnostics.Stopwatch.StartNew();

        for (int i = 0; i < 1000000; i++)
        {
            string str = "The man is old. The is the Good. Them is the bad.";

            //Remove the The if the stirng starts with The.
            if (str.StartsWith("The "))
            {
                str = str.Remove(0, "The ".Length);
                str = str.Insert(0, "@@ ");
            }

            //Remove references The and the.  We can probably 
            //assume a sentence will not end in the.
            str = str.Replace(" The ", " @@ ");
            str = str.Replace(" the ", " @@ ");
        }

        stp.Stop();
        Console.WriteLine(stp.Elapsed);

Answer 3

s = s.Replace（“The”，“@@”）;

Answer 4

C＃console应用程序

static void Main(string[] args)

        {
            Console.Write("Please input your comment: ");
            string str = Console.ReadLine();
            string[] str2 = str.Split(' ');
            replaceStringWithString(str2);
            Console.ReadLine();
        }
        public static void replaceStringWithString(string[] word)
        {
            string[] strArry1 = new string[] { "good", "bad", "hate" };
            string[] strArry2 = new string[] { "g**d", "b*d", "h**e" };
            for (int j = 0; j < strArry1.Count(); j++)
            {
                for (int i = 0; i < word.Count(); i++)
                {
                    if (word[i] == strArry1[j])
                    {
                        word[i] = strArry2[j];
                    }
                    Console.Write(word[i] + " ");
                }
            }
        }

如何替换C＃中的特定单词？

4 个答案: