刪除字符串中的單個字母

Question

我需要幫助來刪除字母，但不是來自傳入數據字符串的單詞。像下面，

String A = "1 2 3A 4 5C 6 ABCD EFGH 7 8D 9"; 

到

String A = "1 2 3 4 5 6 ABCD EFGH 7 8 9"; 

Answer 1

你需要匹配一個字母，並確保沒有信之前和之後。如此匹配

(?<!\p{L})\p{L}(?!\p{L}) 

並替換爲空字符串。

• Look around assertions on regular-expresssion.info

• Unicode properties on regular-expresssion.info

在C＃：

string s = "1 2 3A 4 5C 6 ABCD EFGH 7 8D 9"; 
string result = Regex.Replace(s, @"(?<!\p{L}) # Negative lookbehind assertion to ensure not a letter before 
            \p{L}  # Unicode property, matches a letter in any language 
            (?!\p{L}) # Negative lookahead assertion to ensure not a letter following 
            ", String.Empty, RegexOptions.IgnorePatternWhitespace); 

Answer 2

的 「強制性」 LINQ的方法：

string[] words = A.Split(); 
string result = string.Join(" ", 
     words.Select(w => w.Any(c => Char.IsDigit(c)) ? 
     new string(w.Where(c => Char.IsDigit(c)).ToArray()) : w)); 

此方法查看每個單詞是否包含數字。然後它過濾掉非數字字符並從結果中創建一個新字符串。否則，它只需要這個詞。

Answer 3

這裏來的老同學：

Dim A As String = "1 2 3A 4 5C 6 ABCD EFGH 7 8D 9" 
Dim B As String = "1 2 3 4 5 6 ABCD EFGH 7 8 9" 
Dim sb As New StringBuilder 
Dim letterCount As Integer = 0 
For i = 0 To A.Length - 1 
    Dim ch As Char = CStr(A(i)).ToLower 
    If ch >= "a" And ch <= "z" Then 
    letterCount += 1 
    Else 
    If letterCount > 1 Then sb.Append(A.Substring(i - letterCount, letterCount)) 
    letterCount = 0 
    sb.Append(A(i)) 
    End If 
Next 
Debug.WriteLine(B = sb.ToString) 'prints True