In php, heredoc and nowdoc are two defined strings.

[Php] & lt ;? Php // when you need to write a large text segment with many lines containing single quotation marks and double quotation marks, it is troublesome to escape the text. // You can also use heredoc and nowdoc to define strings $ age = 29; $ str = & lt; cont to write a line, come back... "/> <scripttype = [php] '; $ Str = <'cont': I want to write a row, followed by 2nd rows,' "\, dsafd abc \ t \ r \ n haha $ age cont; echo $ str;/*** the nowdoc write method is the same as heredoc, but the identifiers are enclosed in single quotes. in this way, the parsing of large text is the same as that of single quotes. do not escape \ n \ r \ t, variables, etc. ***/?>