PHP single quote double quotes, PHP string/HMTL/Database Display/and several conversion functions of PHP

* PHP string with single quote delimiter, supports two escapes \ ' and \ \
* PHP string with double quotation mark delimiter, support the following escape (\ ' will output \ ', will also escape \ \):
\ n line break (LF or ASCII characters 0x0A (10))
\ r Enter (CR or ASCII character 0x0D (13))
\ t Horizontal tab (HT or ASCII character 0x09 (9))
\ \ Backslash
\$ dollar Sign
\ "Double quotation marks
\[0-7]{1,3} This regular expression sequence matches a character represented by an octal symbol
\x[0-9a-fa-f]{1,2} This regular expression sequence matches a character that is represented by a hexadecimal symbol

PHP single quote double quotes, PHP string/HMTL/Database Display/and several conversion functions of PHP