Java Regex to remove start/end single quotes but l

问题:

I have data from a CSV file that is enclosed in single quotes, like:

'Company name'
'Price: $43.50'
'New York, New York'

I want to be able to replace the single quotes at the start/end of the value but leave quotes in the data, like:

'Joe's Diner'  should become Joe's Diner

I can do

updateString = theString.replace("^'", "").replace("'$", "");

but I wanted to know if I could combine it to only do one replace.

回答1:

You could use the or operator.

updateString = theString.replaceAll("(^')|('$)","");

See if that works for you :)

回答2:

updateString = theString.replaceFirst("^'(.*)'$", "$1");

Note that the form you have no won't work because replace uses literal strings, not regexes.

This works by using a capturing group (.*), which is referred to with $1 in the replacement text. You could also do something like:

Pattern patt = Pattern.compile("^'(.*)'$"); // could be stored in a static final field.
Matcher matcher = patt.matcher(theString);
boolean matches = matcher.matches();
updateString = matcher.group(1);

Of course, if you're certain there's a single quote at the beginning and end, the simplest solution is:

updateString = theString.substring(1, theString.length() - 1);