Regex for phone number with standard phone number with brackets

Question

This is a question on RegEx in Java. I have looked everywhere but could not find anything similar to what I needed. Also, I have spent hours trying on my own.

I am on the last portion of a school lab coded in Java. I am using Eclipse as my compiler. I have built a membership application using Swing components,

One of my fields is for the user to type in the 10-digit phone number. However, I had to make this a JFormatted text field, masking the text box it in this format: "(###) ###-####". So when the program is loaded, that text box looks like this: "(_) -___"

Now, all I need to do is have a regular expression that will make sure the user types in 10 digits. However, I need it to work with the masked format that I used above. This is what I have so far:

pattern = Pattern.compile("\\d{3}\\s\\d{3}-\\d{4}");
    matcher = pattern.matcher(phoneText.getText());
    if (!matcher.find())
    {
        phoneText.requestFocus();
        JOptionPane.showMessageDialog(null, "Phone entered incorrectly.  Phone should be:\n" +
                "10 numeric digits.",
                "A D D   E R R O R",JOptionPane.ERROR_MESSAGE);
        return;
    }

I believe I have the regEx written to where it accepts the space and the dash in the mask format, but I do not know how to include the parenthesis.

Edit: Adding question in correct format per Andrew Thomas' tip:

What do I need to add to my regEx to include the parenthesis that are already in the formatted text field?

Edit2: Question answered, but adding samples per Bohemians tip so that future students who come across this post can utilize it. Sorry, Im new to this!

Needs to look like:

(123) 456-7890

Answer 1

You have to match ( and ) (That surround the first 3 digits)

Change it to:

pattern = Pattern.compile("\\(\\d{3}\\)\\s\\d{3}-\\d{4}");
                           ^^^      ^^^

As you can see, I added \\ before ( and ). Why?

Some characters have special meaning. And since Regexes are Strings in Java, you need to escape them by \\ (which represents a single \ in Java).

A double backslash escapes special characters to suppress their special meaning, it's like telling:

"Don't take ( as special character, take it as the regular character (".

Answer 2

You can use \\( and \\) to use parentheses, try this:

Pattern.compile("\\(\\d{3}\\)\\s\\d{3}-\\d{4}");