R中的正则表达式语法

Question

I am new regular expression. Suppose I want to get the regular expression for a string "1994-02-14 00:00:00, 12345", now I have a expression:

.*\\d{4}-\\d{2}-\\d{2}[\\d{2}-\\d{2}-\\d{2}]?\,\\d{5}.

But when I use

grepl(pattern = "^.*\\d{4}-\\d{2}-\\d{2}[\\d{2}-\\d{2}-\\d{2}]?\,\\d{5}", x= x )

It gives the following error:'\\,' is an unrecognized escape in character string starting "".*\\d{4}-\\d{2}-\\d{2}[\\d{2}-\\d{2}-\\d{2}]?\\," How should I solve this error? In other words, what is the correct regular expression for the above string?

Thank you!!

Answer 1

您的意思是：

grepl(pattern = "^.*\\d{4}-\\d{2}-\\d{2} (\\d{2}:\\d{2}:\\d{2})?, \\d{5}", x= x )