C language: Escape Character

about ASCII code ,0~31（ Decimal system ） The characters in the range are control characters , They are invisible , Cannot be displayed on the display , You can't even type... From the keyboard , Can only be expressed in the form of escape characters . however , Use it directly ASCII Code memory is inconvenient , It's not easy to understand , therefore , For common control characters ,C Language also defines abbreviations , The complete list is as follows ：

Escape character	significance	ASCII Code value （ Decimal system ）
\a	Ring the bell (BEL)	007
\b	Backspace (BS) , Move the current position to the previous column	008
\f	Change the page (FF), Move the current position to the beginning of the next page	012
\n	Line break (LF) , Moves the current position to the beginning of the next line	010
\r	enter (CR) , Move the current position to the beginning of the line	013
\t	Horizontal TAB (HT)	009
\v	Vertical tabulation (VT)	011
\'	Single quotation marks	039
\"	Double quotes	034
\\	The backslash	092

\n and \t Are the two most commonly used escape characters ：

• \n Used to wrap lines , Let the text output from the beginning of the next line , It has been used many times in the previous chapters ;
• \t Used for occupying , Generally equivalent to four spaces , perhaps tab Key function .

Single quotation marks 、 Double quotes 、 Backslashes are special characters , Can't express directly ：

• Single quotation marks are the beginning and end of character types , To use \' Express , That is to say '\'';
• Double quotes are the beginning and end of a string , To use \" Express , That is to say "abc\"123";
• The backslash is the beginning of the escape character , To use \\ Express , That is to say '\\', perhaps "abc\\123".