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Java regular expressions and dollar sign
4 answers
I'm trying pattern matching expression for a below string. But it doesn't work. could you anybody help me on this ? Only Alphanumeric and underscore allowed inside,Both side
$ sign will be there. Ex strings: Test_1,23_test_2,test3.
String text = "$test_1$";
Pattern p = Pattern.compile("$([A-Za-z0-9_])$");
Matcher m = p.matcher(text);
m.matches();
if (m.find()) {
System.out.println("Matched: " + m.group(1));
} else {
System.out.println("No match.");
}

$ is a regex meta character and should be escaped, try this
Pattern p = Pattern.compile("\\$([A-Za-z0-9_]+)\\$");

Your regex should be:
Pattern p = Pattern.compile("(\\$[A-Za-z0-9_]*\\$)");

You could simply do...
s.matches("\\$[a-zA-Z0-9_]*\\$")