如何从Java字符串中删除[]和（）

Question

I want to remove [, ], ( and ) from my java String. I have tried .replaceAll("(", ""); and .replaceAll("[", ""); but it didn't work. In my program str is read from a file.

String str = "I [need] this ]message () without (this[])";

Answer 1

You probably had the solution, but the replaceAll method does not modify the string. Save the result in a variable:

String str = "I [need] this ]message () without (this[])".replaceAll("[()\\[\\]]", "");

The argument "[()\\\\[\\\\]]" is a regex. The outer [] means: one of the inner symbols. These are ( and ) . Additionally, you want to match [ and ] . But you have to put \\\\ before them because they have that special meaning ("one of").

Answer 2

You need to escape the ( , ) , [ and ] . You can do that with \\\\ . Something like,

String str = "I [need] this ]message () without (this[])";
str = str.replaceAll("[\\[\\]\\(\\)]", "");
System.out.println(str);

Output is

I need this message  without this

Answer 3

You need to add a double backslash before the [ and the ( in your replaceAll statements:

str = str.replaceAll("\\[", "").replaceAll("\\(", "").replaceAll("\\]", "").replaceAll("\\)", "");

(FYI a single \\ will not work as it will evaluate ) as an escaped special character,)