Question

我需要在string中找到所有大写字母。例如

输入：Electronics and Communication Engineering

输出：ECE

Answer 1

如果你坚持正则表达式：

 string source = @"Electronics and Communication Engineering";

 string result = string.Concat(Regex
   .Matches(source, "[A-Z]")
   .OfType<Match>()
   .Select(match => match.Value));

Linq 是一个（更短的）替代方案：

 string result = string.Concat(source.Where(c => c >= 'A' && c <= 'Z'));

Answer 2

使用LINQ：

string text = "Electronics and Communication Engineering";
var capitalLetters = text.Where(c => char.IsUpper(c)).ToArray();

Answer 3

Linq解决方案Example is here：

扩展方法Where将帮助您从给定字符串中获取大写字母。您可以使用String.Join或String.Concat（更好，如 DmitryBychenko 所示）来获得最终输出为字符串。浏览以下代码段

string inputStr = "Electronics and Communication Engineering";
string outputStr=String.Concat(inputStr.Where(x=>Char.IsUpper(x)));
Console.WriteLine(outputStr);

Answer 4

var s = "Electronics and Communication Engineering";

result = string.Concat(s.Select(c => char.IsUpper(c) ? c.ToString() : ""))
            .TrimStart();

查找字符串中的所有大写字母 - 正则表达式C＃

4 个答案: