C /C++标准库 - <cctype> (ctype.h)

1. 概述

This header declares a set of functions to classify and transform individual characters.

2. 函数

2.1 Character classification functions

序号 标签 原型 说明 1 isalnum int isalnum ( int c ); 判断字符c是不是十进制数字或字母 2 isalpha int isalpha ( int c ); 判断字符是否为字母 3 iscntrol int iscntrl ( int c ); 判断是否是控制字符 4 isblank(c++11) int isblank ( int c ); 判断是否为tab(‘\t’)或space(’ ‘)字符 5 isdigit int isdigit ( int c ); Check if character is decimal digit 6 isgraph int isgrapg ( int c ); Checks whether c is a character with graphical representation.(除空格之外的所有打印字符) 7 islower int islower ( int c ); Checks whether c is a lowercase letter. 8 isupper int isupper( int c ) Checks whether c is a uppercase letter. 9 isprint int isprint ( int c ); Checks whether c is a printable character. 10 ispunct int ispunct ( int c ); Checks whether c is a punctuation(标点符号） character. 11 isspace int isspace ( int c ); Checks whether c is a white-space character.(包括空格’ ‘、换页’\f’、换行’\n’、回车’\r’、水平制表’\t’和垂直制表符’\v’) 12 isxdigit int isxdigit ( int c ); Check if character is hexadecimal(十六进制）digit

2.2 Character conversion functions

序号 标签 原型 说明 1 tolower int tolower ( int c ); Convert uppercase letter to lowercase 2 toupper int toupper ( int c ); Convert lowercase letter to uppercase

3. 参考文献

1. http://www.cplusplus.com/reference/cctype/
2. 《C标准库》，P.J. Plauger 著