去正则表达式来检测反斜杠字符

Question

In go, how do I detect \ back slash character itself?

 str := "I have Hello \"World\""
 var validID = regexp.MustCompile(`[.!?]`)

this is how I detect . ! ? characters but

 var validID = regexp.MustCompile(`[\]`)

does not detect the backslash in the string.

How do I denote backslash in go regular expression?

Answer 1

You'll need to escape it, even in a character class; otherwise it will think you're trying to escape the ]:

var validID = regexp.MustCompile(`[\\]`)

But for that matter, you can just get rid of the character class entirely:

var validID = regexp.MustCompile(`\\`)

Also note that the string "I have Hello \"World\"" does not actually contain any backlashes. \" is an escape sequence a double quote. If you want to create a string with backslashes use:

str := "I have Hello \\\"World\\\""

Or

str := `I have Hello \"World\"`

A working demonstration can be found here.