Escape character notes

Java Some letters are prefixed in the language "\“ A character used to express a particular meaning , Such as \0,\t,\n etc. , This is called an escape character (Escape Character).

Java See the backslash as the escape character by default , If you want to in java Using backslashes in requires \

Escape characters are used to represent common ones that cannot be displayed ASCII character . Such as \0,\t,\n etc. , It's called an escape character , Because of the following characters , It's not the original ASCII The character means .

be-all ASCII code Both can be used. "\“+ Numbers ( It's usually 8 Hexadecimal Numbers ) To express .

One 、 Slash and backslash

/ Oblique line (slash), Also known as forward slash ( Forward slash ), Linux The system file path uses .

\ Backslash (backslash), Windows System file path , Program code escape , Unicode Coding, etc .

Two 、 Backslash usage scenario

1. Octal digit escape ASCII

\ + 1 To 3 Eight digit octal number （ Range ’\000’~’\377’）
\0: Null character

2. Hexadecimal digit escape Unicode

\u + Four hexadecimal numbers ;（0~65535）
\u0000: Null character

Commonly used Unicode Character comparison table

The escape of point :. -> \u002E
The escape of the dollar sign :$ -> \u0024
The escape of the power sign :^ -> \u005E
The escape of the left brace :{ -> \u007B
The escape of the left square bracket :[ -> \u005B
Escape of left parenthesis :( -> \u0028
The escape of the vertical line :| -> \u007C
The escape of the right parenthesis :) -> \u0029
The escape of asterisk :* -> \u002A
The escape of the plus sign :+ -> \u002B
The escape of question mark :? -> \u003F
Escape of backslash : -> \u005C

3. Ordinary characters represent special characters

Serial number	Escape character	meaning	ASCII Code value （ Decimal system ）
1	\a	Ring the bell (BEL)	007
2	\b	Backspace (BS) , Move the current position to the previous column	008
3	\f	Change the page (FF), Move the current position to the beginning of the next page	012
4	\n	Line break (LF) , Moves the current position to the beginning of the next line	010
5	\r	enter (CR) , Move the current position to the beginning of the line	013
6	\t	Horizontal TAB (HT) （ Skip to the next TAB Location ）	009
7	\v	Vertical tabulation (VT)	011
8	\	Represents a backslash character ""	092
9	’	Represents a single quotation mark （ apostrophe ） character	039
10	"	Represents a double quote character	034
11	?	Represents a question mark	063
12	\0	Null character (NUL)	000
13	\ddd	1 To 3 Any character represented by an octal number	Three octal
14	\xhh	Any character represented by hexadecimal	Hexadecimal