import java.util.regex.*;

class RegexDemo{

public static void main (String[] args) throws java.lang.Exception{

//matches numbers only

String regexStr = "^[0-9]*$";

System.out.println(Pattern.matches(regexStr,"97845613000"));

System.out.println(Pattern.matches(regexStr,"19432"));

System.out.println(Pattern.matches(regexStr,"519Ah"));

//matches 10-digit numbers only

regexStr = "^[0-9]{10}$";

System.out.println(Pattern.matches(regexStr,"6576767"));

System.out.println(Pattern.matches(regexStr,"9784561300"));

System.out.println(Pattern.matches(regexStr,"F784561300"));

//matches numbers and dashes, any order really.

regexStr = "^[0-9\\-]*$";

System.out.println(Pattern.matches(regexStr,"97-8456-13-0-0"));

System.out.println(Pattern.matches(regexStr,"9-7-8-4-5-6-1-3-0-0"));

//matches 9999999999, 1-999-999-9999 and 999-999-9999

regexStr = "^(1\\-)?[0-9]{3}\\-?[0-9]{3}\\-?[0-9]{4}$";

System.out.println(Pattern.matches(regexStr,"9784561300"));

System.out.println(Pattern.matches(regexStr,"9-784561300"));

System.out.println(Pattern.matches(regexStr,"978-456-1300"));

System.out.println(Pattern.matches(regexStr,"97-8456-13-0-0"));

}

}