7.5.2 Character operation functions

Character operation functions are as follows.

Table 7.4

Character operation Functions

Function Name

Outline

isalnum

Identification of ASCII letter or numeral

isalpha

Identification of ASCII letter

isascii

Identification of ASCII code

iscntrl

Identification of control character

isdigit

Identification of decimal number

isgraph

Identification of display character other than space

islower

Identification of lower-case character

isprint

Identification of display character

ispunct

Identification of delimiter character

isspace

Identification of space/tab/carriage return/line feed/vertical tab/page feed

isupper

Identification of upper-case character

isxdigit

Identification of hexadecimal number

toascii

Judges if a character is an ASCII code

tolower

Conversion from upper-case to lower-case (not converted if argument is not in upper-case)

toupper

Conversion from lower-case to upper-case (not converted if argument is not in lower-case)