修剪字符串中的最后一个字符

"Hello! world!".TrimEnd('!');

read more

我注意到,在这类问题中,几乎每个人都建议删除给定字符串的最后一个字符。但这并不符合Trim方法的定义。

修剪-删除所有引用 中的空白字符

MSDN-Trim

在这个定义下,只从字符串中删除最后一个字符是不好的解决方案。

所以,如果我们想“修剪字符串的最后一个字符”,我们应该这样做

public static class MyExtensions
{
  public static string TrimLastCharacter(this String str)
  {
     if(String.IsNullOrEmpty(str)){
        return str;
     } else {
        return str.TrimEnd(str[str.Length - 1]);
     }
  }
}

注意

else { return str.Remove(str.Length - 1); }

String withoutLast = yourString.Substring(0,(yourString.Length - 1));

if (yourString.Length > 1)
    withoutLast = yourString.Substring(0, yourString.Length - 1);

if (yourString.Length > 1)
    withoutLast = yourString.TrimEnd().Substring(0, yourString.Length - 1);

…以防要从结尾删除非空白字符。

        string s1 = "Hello! world!";
        string s2 = s1.Trim('!');

最后修剪的另一个例子 性格 从字符串:

string outputText = inputText.Remove(inputText.Length - 1, 1);

您可以将其放入扩展方法中,并防止其为空字符串等。

return( (str).Remove(str.Length-1) );

string helloOriginal = "Hello! World!";
string newString = helloOriginal.Substring(0,helloOriginal.LastIndexOf('!'));

string s1 = "Hello! world!"
string s2 = s1.Substring(0, s1.Length - 1);
Console.WriteLine(s1);
Console.WriteLine(s2);

你也可以用这个:

public static class Extensions
 {

        public static string RemovePrefix(this string o, string prefix)
        {
            if (prefix == null) return o;
            return !o.StartsWith(prefix) ? o : o.Remove(0, prefix.Length);
        }

        public static string RemoveSuffix(this string o, string suffix)
        {
            if(suffix == null) return o;
            return !o.EndsWith(suffix) ? o : o.Remove(o.Length - suffix.Length, suffix.Length);
        }

    }

非常简单:

结构=str.删除( 结构长度- 1 );

internal static class String
{
    public static string TrimEndsCharacter(this string target, char character) => target?.TrimLeadingCharacter(character).TrimTrailingCharacter(character);
    public static string TrimLeadingCharacter(this string target, char character) => Match(target?.Substring(0, 1), character) ? target.Remove(0,1) : target;
    public static string TrimTrailingCharacter(this string target, char character) => Match(target?.Substring(target.Length - 1, 1), character) ? target.Substring(0, target.Length - 1) : target;

    private static bool Match(string value, char character) => !string.IsNullOrEmpty(value) && value[0] == character;
}

用法

"!Something!".TrimLeadingCharacter('X'); // Result '!Something!' (No Change)
"!Something!".TrimTrailingCharacter('S'); // Result '!Something!' (No Change)
"!Something!".TrimEndsCharacter('g'); // Result '!Something!' (No Change)

"!Something!".TrimLeadingCharacter('!'); // Result 'Something!' (1st Character removed)
"!Something!".TrimTrailingCharacter('!'); // Result '!Something' (Last Character removed)
"!Something!".TrimEndsCharacter('!'); // Result 'Something'  (End Characters removed)

"!!Something!!".TrimLeadingCharacter('!'); // Result '!Something!!' (Only 1st instance removed)
"!!Something!!".TrimTrailingCharacter('!'); // Result '!!Something!' (Only Last instance removed)
"!!Something!!".TrimEndsCharacter('!'); // Result '!Something!'  (Only End instances removed)

稍微修改了@Damian Leszczyski-Vash的版本,确保只删除一个特定的字符。

public static class StringExtensions
{
    public static string TrimLastCharacter(this string str, char character)
    {
        if (string.IsNullOrEmpty(str) || str[str.Length - 1] != character)
        {
            return str;
        }
        return str.Substring(0, str.Length - 1);
    }
}

您可以将标记为答案的代码编写为:

public static class StringExtensions
{
    public static string TrimLastCharacters(this string str) => string.IsNullOrEmpty(str) ? str : str.TrimEnd(str[^1]);
}

但是,如答案中所述,这将删除最后一个字符的所有出现。如果你只想移除 最后一个字符

    public static string RemoveLastCharacter(this string str) => string.IsNullOrEmpty(str) ? str : str[..^1];

对C#8中新内容的快速解释:

^ .. 称为“范围运算符”。 ^1 是一条捷径 arr.length - 1 . 您可以使用 arr[1..] 或最后一项之前的所有项 arr[..^1] . 这些只是几个简单的例子。有关详细信息,请参阅 https://docs.microsoft.com/en-us/dotnet/csharp/whats-new/csharp-8 ,“指数和范围”部分。

即。:

static class Extensions
{
        public static string RemoveLastChars(this String text, string suffix)
        {            
            char[] trailingChars = suffix.ToCharArray();

            if (suffix == null) return text;
            return text.TrimEnd(trailingChars);
        }

}

string _ManagedLocationsOLAP = string.Empty;
_ManagedLocationsOLAP = _validManagedLocationIDs.RemoveLastChars(",");          

string input = "Hello! world!";

string output = Regex.Replace(input, "(world)!", "$1", RegexOptions.Multiline | RegexOptions.Singleline);

// result: "Hello! world"