C language --- character, --- character

C language --- character, --- character

1. triplicate character (tri-letter word): It is a combination of three characters to represent other characters. The triplicate character can be used when no character exists.

?? ([

??) ]

??! |

?? <{

?> }

?? '^

?? = #

?? /\

?? -~

2. escape characters

Visible characters:

\? ---- Used for multiple? To prevent being interpreted as a trigger.

\ "---- Double quotation marks inside the string

\ '---- Single quotation marks of character constants'

\ ---- Indicates a backslash to prevent escape characters

Invisible characters:

\ A ---- warning character to generate visible or audible signals

\ B (backspace) ---- return key

\ F ---- paper feed character (Form feed)

\ N (new line) ---- line feed

\ R (return) ----- press enter (do not wrap)

\ T (tab) ---- horizontal tab

\ V ---- vertical Tab

\ Ddd ---- indicates 1 ~ Three octal characters

\ Xddd ---- indicates 1 ~ 3 characters represented by hexadecimal numbers

Note:

1. in linux, the third element is skipped by default in gcc 4.4.7.

2. in linux, \ n is equivalent to \ r \ n in win.

3. \ ddd \ xddd

For example, \ x101 hexadecimal 101 represents 65 in decimal format, and \ x101 represents the letter.