Telehpone number validator reg expression is below

For a telephone number validator we need a regualar expression that does the following

Start with an ( so the carrot character ^ Then we should have a ( as a first character [(] . \ is used as an escape character for ( .Then {1} quantifier means there can be only 1 ( Then there will be 3 nos from 1-9 . so we use quantifier {3} The there should be only 1 closing parenthesis [)]{1}

Then there should be only one blank space [ ]{1}

And then 3 nos from 1 to 9 }[0-9]{3} Then one - .[-]{1} Another 4 nos from 1-9 [0-9]{4} And it should end after that. that is nothing after that so we close the bracket that we started right after the carrot character ^ in the very beginning and put dollar sign $

   //^([\(]{1}[0-9]{3}[\)]{1}[ ]{1}[0-9]{3}[\-]{1}[0-9]{4})$

Code to test the above regular expression is below

   String phoneNumber1 = "1234567890";
   String phoneNumber2= "(123) 456-7890";
   String phoneNumber3 = "123 456-7890";
   String phoneNumber4 = "(123)456-7890";

   System.out.println("phone1 "+ phoneNumber1.matches("^([\\(]{1}[0-9]{3}[\\)]{1}[ ]{1}[0-9]{3}[\\-]{1}[0-9]{4})$"));
   System.out.println("phone2 "+ phoneNumber2.matches("^([\\(]{1}[0-9]{3}[\\)]{1}[ ]{1}[0-9]{3}[\\-]{1}[0-9]{4})$"));
   System.out.println("phone3 "+ phoneNumber3.matches("^([\\(]{1}[0-9]{3}[\\)]{1}[ ]{1}[0-9]{3}[\\-]{1}[0-9]{4})$"));
   System.out.println("phone4 "+ phoneNumber4.matches("^([\\(]{1}[0-9]{3}[\\)]{1}[ ]{1}[0-9]{3}[\\-]{1}[0-9]{4})$"));