在这个C语言程序中，这两个反斜杠是起什么作用的啊

在这个C语言程序中，这两个反斜杠是起什么作用的啊？
程序运行后并没有这两个反斜杠，我只知道\n是换行

这是转义字符，因为字符串本身是在两个引号之间的，那么如果字符串中本身就有引号字符，就必须用转义字符来表示，否则就乱了

输出一个反斜杠

C Character Constants
A “character constant” is formed by enclosing a single character from the representable character set within single quotation marks (' '). Character constants are used to represent characters in the execution character set.

Syntax

character-constant :

'c-char-sequence'
L'c-char-sequence'

c-char-sequence :

c-char
c-char-sequence c-char

c-char :

Any member of the source character set except the single quotation mark ('), backslash (), or newline character
escape-sequence

escape-sequence :

simple-escape-sequence
octal-escape-sequence
hexadecimal-escape-sequence

simple-escape-sequence : one of

\a \b \f \n \r \t \v
\' \" \\ \?

octal-escape-sequence :

\ octal-digit
\ octal-digit octal-digit
\ octal-digit octal-digit octal-digit

hexadecimal-escape-sequence :

\x hexadecimal-digit
hexadecimal-escape-sequence hexadecimal-digit