c库

以下各行分别表示functions，Returns

stdlib.h

atof() A value of type double that is produced from the string argument
atoi() A value of type int that is produced from the string argument
atol() A value of type long that is produced from the string argument
atoll() A value of type long long that is produced from the string argument

 

ctype.h

islower() Lowercase letter
isupper() Uppercase letter
isalpha() Uppercase or lowercase letter
isalnum() Uppercase or lowercase letter or a digit
iscntrl() Control character
isprint() Any printing character including space
isgraph() Any printing character except space
isdigit() Decimal digit ('0' to '9')
isxdigit() Hexadecimal digit ('0' to '9', 'A' to 'F', 'a' to 'f')
isblank() Standard blank characters (space, '\t')
isspace() Whitespace character (space, '\n', '\t', '\v', '\r', '\f')
ispunct() Printing character for which isspace() and isalnum() return false

 

wchar.h

iswlower() Lowercase letter
iswupper() Uppercase letter
iswalnum() Uppercase or lowercase letter
iswcntrl() Control character
iswprint() Any printing character including space
iswgraph() Any printing character except space
iswdigit() Decimal digit (L'0' to L'9')
iswxdigit() Hexadecimal digit (L'0' to L'9', L'A' to L'F', L'a' to L'f')
iswblank() Standard blank characters (space, L'\t')
iswspace() Whitespace character (space, L'\n', L'\t', L'\v', L'\r', L'\f')
iswpunct() Printing character for which iswspace() and iswalnum() return false