C++的边边角角扫盲

指针数组：C/C++语言中，数组元素全为指针的数组。一维指针数组的定义形式：“类型名 *数组标识符[数组长度]”。比如：int *arr[100].

<cctype> (ctype.h)

Character classification functions

They check whether the character passed as parameter belongs to a certain category:

isalnum

Check if character is alphanumeric  (function )

isalpha

Check if character is alphabetic  (function )

isblank 

Check if character is blank  (function )

iscntrl

Check if character is a control character  (function )

isdigit

Check if character is decimal digit  (function )

isgraph

Check if character has graphical representation  (function )

islower

Check if character is lowercase letter  (function )

isprint

Check if character is printable  (function )

ispunct

Check if character is a punctuation character  (function )

isspace

Check if character is a white-space  (function )

isupper

Check if character is uppercase letter  (function )

isxdigit

Check if character is hexadecimal digit  (function )

Character conversion functions

Two functions that convert between letter cases:

tolower

Convert uppercase letter to lowercase  (function )

toupper

Convert lowercase letter to uppercase  (function )