检查MyString [1]是否为字母字符？ [英] Check if MyString[1] is an alphabetical character?

问题描述

我有一个字符串，让它 MyStr 。我试图摆脱字符串中的每个非字母字符。比如，在IM的MSN和Skype，人们把他们的显示名称像 [ - Bobby - ] 。我想删除该字符串中不是字母字符的所有内容，所以我留下的是名称。

I have a string, lets call it MyStr. I am trying to get rid of every non-alphabetical character in the string. Like, in IM's like MSN and Skype, people put their display names like [-Bobby-]. I would like to remove everything in that string that is not an alphabetical character, so all I am left with, is the "name".

我如何做到这一点德尔福？我正在考虑创建一个 TStringlist 并存储每个有效字符，然后使用 IndexOf 来检查字符

How can I do that in Delphi? I was thinking about creating a TStringlist and store each valid character in there, and then use IndexOf to check if the char is valid, but I was hoping for an easier way.

推荐答案

最简单的方法是

function GetAlphaSubstr(const Str: string): string;
const
  ALPHA_CHARS = ['a'..'z', 'A'..'Z'];
var
  ActualLength: integer;
  i: Integer;
begin
  SetLength(result, length(Str));
  ActualLength := 0;
  for i := 1 to length(Str) do
    if Str[i] in ALPHA_CHARS then
    begin
      inc(ActualLength);
      result[ActualLength] := Str[i];
    end;
  SetLength(Result, ActualLength);
end;

但这只会将英文字母视为字母字符。它甚至不会考虑极为重要的瑞典字母Å，Ä和Ö作为字母字符！

but this will only consider English letters as "alphabetical characters". It will not even consider the extremely important Swedish letters Å, Ä, and Ö as "alphabetical characters"!

稍微更复杂的是

function GetAlphaSubstr2(const Str: string): string;
var
  ActualLength: integer;
  i: Integer;
begin
  SetLength(result, length(Str));
  ActualLength := 0;
  for i := 1 to length(Str) do
    if Character.IsLetter(Str[i]) then
    begin
      inc(ActualLength);
      result[ActualLength] := Str[i];
    end;
  SetLength(Result, ActualLength);
end;

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