Partilhar via


Character Classification

Each of these routines tests a specified single-byte character, wide character, or multibyte character for satisfaction of a condition. (By definition, the ASCII character set between 0 and 127 are a subset of all multibyte-character sets. For example, Japanese katakana includes ASCII as well as non-ASCII characters.)

The test conditions are affected by the setting of the LC_CTYPE category setting of the locale; see setlocale for more information. The versions of these functions without the _l suffix use the current locale for this locale-dependent behavior; the versions with the _l suffix are identical except that they use the locale parameter passed in instead.

Generally these routines execute faster than tests you might write and should be favored over. For example, the following code executes slower than a call to isalpha(c):

if ((c >= 'A') && (c <= 'Z')) || ((c >= 'a') && (c <= 'z'))
    return TRUE;

Character-Classification Routines

Routine

Character test condition

.NET Framework equivalent

isalnum, iswalnum, _isalnum_l, _iswalnum_l, _ismbcalnum, _ismbcalnum_l, _ismbcalpha, _ismbcalpha_l, _ismbcdigit, _ismbcdigit_l

Alphanumeric

System::Char::IsLetterOrDigit.

_ismbcalnum, _ismbcalnum_l, _ismbcalpha, _ismbcalpha_l, _ismbcdigit, _ismbcdigit_l

Alphanumeric

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

isalpha, iswalpha, _isalpha_l, _iswalpha_l, _ismbcalnum, _ismbcalnum_l, _ismbcalpha, _ismbcalpha_l, _ismbcdigit, _ismbcdigit_l

Alphabetic

System::Char::IsLetter

__isascii, iswascii

ASCII

System::Char::IsLetter

isblank, iswblank, _isblank_l, _iswblank_l, _ismbcsblank, _ismbcsblank_l

Blank (space or horizontal tab)

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

iscntrl, iswcntrl, _iscntrl_l, _iswcntrl_l

Control

System::Char::IsControl

__iscsym, __iswcsym, __iscsymf, __iswcsymf, _iscsym_l, _iswcsym_l, _iscsymf_l, _iswcsymf_l

Letter, underscore, or digit

System::Char::IsControl

__iscsym, __iswcsym, __iscsymf, __iswcsymf, _iscsym_l, _iswcsym_l, _iscsymf_l, _iswcsymf_l

Letter or underscore

System::Char::IsControl

isdigit, iswdigit, _isdigit_l, _iswdigit_l, _ismbcalnum, _ismbcalnum_l, _ismbcalpha, _ismbcalpha_l, _ismbcdigit, _ismbcdigit_l

Decimal digit

System::Char::IsDigit

isgraph, iswgraph, _isgraph_l, _iswgraph_l, _ismbcgraph, _ismbcgraph_l, _ismbcprint, _ismbcprint_l, _ismbcpunct, _ismbcpunct_l, _ismbcblank, _ismbcblank_l, _ismbcspace, _ismbcspace_l

Printable other than space

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

islower, iswlower, _islower_l, _iswlower_l, _ismbclower, _ismbclower_l, _ismbcupper, _ismbcupper_l

Lowercase

System::Char::IsLower

_ismbchira, _ismbchira_l, _ismbckata, _ismbckata_l

Hiragana

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

_ismbchira, _ismbchira_l, _ismbckata, _ismbckata_l

Katakana

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

_ismbclegal, _ismbclegal_l, _ismbcsymbol, _ismbcsymbol_l

Legal multibyte character

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

_ismbcl0, _ismbcl0_l, _ismbcl1, _ismbcl1_l, _ismbcl2, _ismbcl2_l

Japan-level 0 multibyte character

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

_ismbcl0, _ismbcl0_l, _ismbcl1, _ismbcl1_l, _ismbcl2, _ismbcl2_l

Japan-level 1 multibyte character

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

_ismbcl0, _ismbcl0_l, _ismbcl1, _ismbcl1_l, _ismbcl2, _ismbcl2_l

Japan-level 2 multibyte character

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

_ismbclegal, _ismbclegal_l, _ismbcsymbol, _ismbcsymbol_l

Non-alphanumeric multibyte character

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

isprint, iswprint, _isprint_l, _iswprint_l, _ismbcgraph, _ismbcgraph_l, _ismbcprint, _ismbcprint_l, _ismbcpunct, _ismbcpunct_l, _ismbcblank, _ismbcblank_l, _ismbcspace, _ismbcspace_l

Printable

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

ispunct, iswpunct, _ispunct_l, _iswpunct_l, _ismbcgraph, _ismbcgraph_l, _ismbcprint, _ismbcprint_l, _ismbcpunct, _ismbcpunct_l, _ismbcblank, _ismbcblank_l, _ismbcspace, _ismbcspace_l

Punctuation

System::Char::IsPunctuation

isspace, iswspace, _isspace_l, _iswspace_l, _ismbcgraph, _ismbcgraph_l, _ismbcprint, _ismbcprint_l, _ismbcpunct, _ismbcpunct_l, _ismbcblank, _ismbcblank_l, _ismbcspace, _ismbcspace_l

White-space

System::Char::IsWhiteSpace

Isupper, iswupper, _ismbclower, _ismbclower_l, _ismbcupper, _ismbcupper_l

Uppercase

System::Char::IsUpper

_isctype, iswctype, _isctype_l, _iswctype_l

Property specified by desc argument

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

isxdigit, iswxdigit, _isxdigit_l, _iswxdigit_l

Hexadecimal digit

System::Char::IsNumber

_mbclen, mblen, _mblen_l

Return length of valid multibyte character; result depends on LC_CTYPE category setting of current locale

Not applicable. To call the standard C function, use PInvoke. For more information, see Platform Invoke Examples.

See Also

Reference

Run-Time Routines by Category