java.util.regex.PatternSyntaxException: Dangling meta character '?' near index 0

Hi everyone

I am getting this error "java.util.regex.PatternSyntaxException: Dangling meta character '?' near index 0"
I am reading an input file which has data like

?xyz

In my code I am replacing the binary equivalent of ? that is "\u003F" with ""
text = text.replaceAll("\u003F","");

But I still get this error...
Any help is greatly appreciated
Thanks in advance.

The replaceAll() method takes a regex as the first parameter. And the "?" has special meaning in a regex. If you want it to behave as an literal question mark, then you will need to escape it.

text = text.replaceAll("\\?","");

Henry

Unicode characters are parsed and substituted before the source file is compiled. Your line of code is exactly the same as You need to escape the ? as Henry suggested. Keep in mind that the regular expression escape character has special meaning in Java Strings as well, so you need to escape that one as well.

Henry Wong wrote:The replaceAll() method takes a regex as the first parameter. And the "?" has special meaning in a regex. If you want it to behave as an literal question mark, then you will need to escape it.

text = text.replaceAll("\\?","");

Henry

Hi Henry
I tried and that didn't work either.

"Didn't work" in what way?

I used the code

text = text.replaceAll("\\?","");
instead of
text = text.replaceAll("\u003F","");

but I am still getting the error "java.util.regex.PatternSyntaxException: Dangling meta character '?' near index 0"

I am sorry .

The code is working fine now

I forgot to comment the line
text=text.replaceAll("\u003F","")

before adding the new code.
Really sorry for the miscommunication.

Many thanks for all your help everyone

You're welcome.

By the way, there is now also a String.replace method that takes CharSequences and does not use regular expressions. Since String implements CharSequence it would be much easier to use that one: