Char.IsLetter 方法

表示指定的 Unicode 字元是否分類為 Unicode 字母。Indicates whether the specified Unicode character is categorized as a Unicode letter.

public:
 static bool IsLetter(char c);

public static bool IsLetter (char c);

static member IsLetter : char -> bool

Public Shared Function IsLetter (c As Char) As Boolean

參數

傳回

範例

下列程式碼範例將IsLetter示範。The following code example demonstrates IsLetter.

using namespace System;
int main()
{
   char ch = '8';
   Console::WriteLine( Char::IsLetter( ch ) ); // False
   Console::WriteLine( Char::IsLetter(  "sample string", 7 ) ); // True
}

using System;

public class IsLetterSample {
    public static void Main() {
        char ch = '8';

        Console.WriteLine(Char.IsLetter(ch));					// False
        Console.WriteLine(Char.IsLetter("sample string", 7));	// True
    }
}

Module IsLetterSample

    Sub Main()

        Dim ch8 As Char
        ch8 = "8"c

        Console.WriteLine(Char.IsLetter(ch8))                   ' Output: "False"
        Console.WriteLine(Char.IsLetter("sample string", 5))    ' Output: "True"

    End Sub

End Module

備註

這個方法Char會判斷是否為任何 Unicode 字母分類的成員。This method determines whether a Char is a member of any category of Unicode letter. Unicode 字母包括下列各項：Unicode letters include the following:

• 大寫字母，例如 U + 0041 （拉丁大寫字母 A）到 U + 005A （拉丁大寫字母 Z），或 U + 0400 （西瑞爾文大寫字母 IE 含抑音符號）到 U + 042F （斯拉夫文大寫字母 YA）。Uppercase letters, such as U+0041 (LATIN CAPITAL LETTER A) through U+005A (LATIN CAPITAL LETTER Z), or U+0400 (CYRILLIC CAPITAL LETTER IE WITH GRAVE) through U+042F (CYRILLIC CAPITAL LETTER YA). 這些字元是UnicodeCategory.UppercaseLetter類別目錄的成員。These characters are members of the UnicodeCategory.UppercaseLetter category.

• 小寫字母，例如 U + 0061 （拉丁小型字母 A）到 U + 007A （拉丁文 small 字母 Z），或 U + 03AC （希臘文小寫字母 ALPHA 含 TONOS）到 U + 03CE （希臘文小寫字母 OMEGA 加上 TONOS）。Lowercase letters, such as U+0061 (LATIN SMALL LETTER A) through U+007A (LATIN SMALL LETTER Z), or U+03AC (GREEK SMALL LETTER ALPHA WITH TONOS) through U+03CE (GREEK SMALL LETTER OMEGA WITH TONOS). 這些字元是UnicodeCategory.LowercaseLetter類別目錄的成員。These characters are members of the UnicodeCategory.LowercaseLetter category.

• 標題大小寫字母，例如 U + 01C5 （拉丁文大寫字母 D 與小寫字母 Z 加上抑揚符）或 U + 1FFC （希臘文大寫字母 OMEGA 與 PROSGEGRAMMENI）。Title case letters, such as U+01C5 (LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON) or U+1FFC (GREEK CAPITAL LETTER OMEGA WITH PROSGEGRAMMENI). 這些字元是UnicodeCategory.TitlecaseLetter類別目錄的成員。These characters are members of the UnicodeCategory.TitlecaseLetter category.

• 修飾詞，例如 U + 02B0 （修飾詞字母 SMALL H）到 U + 02C1 （修飾詞的反向喉塞音符號），或 U + 1D2C （修飾詞字母大寫 A）到 U + 1D61 （修飾詞字母小型的標號）。Modifiers, such as U+02B0 (MODIFIER LETTER SMALL H) through U+02C1 (MODIFIER LETTER REVERSED GLOTTAL STOP), or U+1D2C (MODIFIER LETTER CAPITAL A) through U+1D61 (MODIFIER LETTER SMALL CHI). 這些字元是UnicodeCategory.ModifierLetter類別目錄的成員。These characters are members of the UnicodeCategory.ModifierLetter category.

• 其他字母，例如 u + 05D0 （希伯來文字母 ALEF）到 u + 05EA （希伯來文字母 TAV）、u + 0621 （阿拉伯文字母喉塞音符）到 u + 063A （阿拉伯文字母 GHAIN），或 u + 4E00 （<cjk 表意字元，First >）到 u + 9FC3 （<cjk 表意字元，Last>）。Other letters, such as U+05D0 (HEBREW LETTER ALEF) through U+05EA (HEBREW LETTER TAV), U+0621 (ARABIC LETTER HAMZA) through U+063A (ARABIC LETTER GHAIN), or U+4E00 (<CJK Ideograph, First>) through U+9FC3 (<CJK Ideograph, Last>). 這些字元是UnicodeCategory.OtherLetter類別目錄的成員。These characters are members of the UnicodeCategory.OtherLetter category.

另請參閱

• Boolean

指示指定的字串中指定位置處的字元是否分類為 Unicode 字母。Indicates whether the character at the specified position in a specified string is categorized as a Unicode letter.

public:
 static bool IsLetter(System::String ^ s, int index);

public static bool IsLetter (string s, int index);

static member IsLetter : string * int -> bool

Public Shared Function IsLetter (s As String, index As Integer) As Boolean

參數

傳回

例外狀況

範例

下列程式碼範例將IsLetter示範。The following code example demonstrates IsLetter.

using namespace System;
int main()
{
   char ch = '8';
   Console::WriteLine( Char::IsLetter( ch ) ); // False
   Console::WriteLine( Char::IsLetter(  "sample string", 7 ) ); // True
}

using System;

public class IsLetterSample {
    public static void Main() {
        char ch = '8';

        Console.WriteLine(Char.IsLetter(ch));					// False
        Console.WriteLine(Char.IsLetter("sample string", 7));	// True
    }
}

Module IsLetterSample

    Sub Main()

        Dim ch8 As Char
        ch8 = "8"c

        Console.WriteLine(Char.IsLetter(ch8))                   ' Output: "False"
        Console.WriteLine(Char.IsLetter("sample string", 5))    ' Output: "True"

    End Sub

End Module

備註

字串中的字元位置會從零開始編制索引。Character positions in a string are indexed starting from zero.

這個方法會判斷字串中指定索引位置處的字元是否為任何 Unicode 字母分類的成員。This method determines whether the character at a specified index position in a string is a member of any category of Unicode letter. Unicode 字母包括下列各項：Unicode letters include the following:

• 大寫字母，例如 U + 0041 （拉丁大寫字母 A）到 U + 005A （拉丁大寫字母 Z），或 U + 0400 （西瑞爾文大寫字母 IE 含抑音符號）到 U + 042F （斯拉夫文大寫字母 YA）。Uppercase letters, such as U+0041 (LATIN CAPITAL LETTER A) through U+005A (LATIN CAPITAL LETTER Z), or U+0400 (CYRILLIC CAPITAL LETTER IE WITH GRAVE) through U+042F (CYRILLIC CAPITAL LETTER YA). 這些字元是UnicodeCategory.UppercaseLetter類別目錄的成員。These characters are members of the UnicodeCategory.UppercaseLetter category.

• 小寫字母，例如 U + 0061 （拉丁小型字母 A）到 U + 007A （拉丁文 small 字母 Z），或 U + 03AC （希臘文小寫字母 ALPHA 含 TONOS）到 U + 03CE （希臘文小寫字母 OMEGA 加上 TONOS）。Lowercase letters, such as U+0061 (LATIN SMALL LETTER A) through U+007A (LATIN SMALL LETTER Z), or U+03AC (GREEK SMALL LETTER ALPHA WITH TONOS) through U+03CE (GREEK SMALL LETTER OMEGA WITH TONOS). 這些字元是UnicodeCategory.LowercaseLetter類別目錄的成員。These characters are members of the UnicodeCategory.LowercaseLetter category.

• 標題大小寫字母，例如 U + 01C5 （拉丁文大寫字母 D 與小寫字母 Z 加上抑揚符）或 U + 1FFC （希臘文大寫字母 OMEGA 與 PROSGEGRAMMENI）。Title case letters, such as U+01C5 (LATIN CAPITAL LETTER D WITH SMALL LETTER Z WITH CARON) or U+1FFC (GREEK CAPITAL LETTER OMEGA WITH PROSGEGRAMMENI). 這些字元是UnicodeCategory.TitlecaseLetter類別目錄的成員。These characters are members of the UnicodeCategory.TitlecaseLetter category.

• 修飾詞，例如 U + 02B0 （修飾詞字母 SMALL H）到 U + 02C1 （修飾詞的反向喉塞音符號），或 U + 1D2C （修飾詞字母大寫 A）到 U + 1D61 （修飾詞字母小型的標號）。Modifiers, such as U+02B0 (MODIFIER LETTER SMALL H) through U+02C1 (MODIFIER LETTER REVERSED GLOTTAL STOP), or U+1D2C (MODIFIER LETTER CAPITAL A) through U+1D61 (MODIFIER LETTER SMALL CHI). 這些字元是UnicodeCategory.ModifierLetter類別目錄的成員。These characters are members of the UnicodeCategory.ModifierLetter category.

• 其他字母，例如 u + 05D0 （希伯來文字母 ALEF）到 u + 05EA （希伯來文字母 TAV）、u + 0621 （阿拉伯文字母喉塞音符）到 u + 063A （阿拉伯文字母 GHAIN），或 u + 4E00 （<cjk 表意字元，First >）到 u + 9FC3 （<cjk 表意字元，Last>）。Other letters, such as U+05D0 (HEBREW LETTER ALEF) through U+05EA (HEBREW LETTER TAV), U+0621 (ARABIC LETTER HAMZA) through U+063A (ARABIC LETTER GHAIN), or U+4E00 (<CJK Ideograph, First>) through U+9FC3 (<CJK Ideograph, Last>). 這些字元是UnicodeCategory.OtherLetter類別目錄的成員。These characters are members of the UnicodeCategory.OtherLetter category.

另請參閱

• Boolean