为什么Regex.Replace留下括号？

Question

Lets say you have:

string result = Regex.Replace("people (MANY)", "(many)", "", RegexOptions.IgnoreCase);

Then after this result will be people () . Why is this and how do I alter the regex replace to remove the brackets too?

Answer 1

In regex there is a set of characters that can have a special meaning (\\, *, +, ?, |, {, [, (,), ^, $,., #, and white space), if you want them always represented in your pattern you need to escape them.

There is a general function Regex.Escape that will go through the above list and escape every instance it finds for you.

Regex.Escape("(many)") // this becomes \(many\)

Answer 2

You have to escape them: http://msdn.microsoft.com/en-us/library/4edbef7e(v=vs.110).aspx

The following characters have to be escaped in Regular Expressions because they have a meaning in pattern matching:

. $ ^ { [ ( | ) * + ? \\

You can escape this special chars with the backslash \\ in your case \\( and \\)

Your code changed accordingly:

string result = Regex.Replace("people (MANY)", "\(many\)", "", RegexOptions.IgnoreCase);

Answer 3

That is because the parenthesis have a meaning in Regex patterns. They define a capturing group .

Escape the parenthesis, so that they are not seen as special characters but as parenthesis:

string result = Regex.Replace("people (MANY)", @"\(many\)", "", RegexOptions.IgnoreCase);

Answer 4

change it to

string result = Regex.Replace("people (MANY)", @"\(many\)", "", RegexOptions.IgnoreCase);

The () mean something special to the regex engine, so you have to escape them.

Answer 5

方括号是用于分组的特殊字符，您需要对其进行转义：

Regex.Replace("people (MANY)", @"\(many\)", "", RegexOptions.IgnoreCase);

Answer 6

Parenthesis in a regex let you define a capture group . You need to escape them for them to be considered as regular characters

Answer 7

Parentheses have a special meaning in regexes -- they're for capturing (so in the replace you could use $1 and it would give you what was in the parens). If you want a literal you have to escape them: \\(