Valid Phone Number

main.java

package com.company;

public class Main {

    public static void main(String[] args) {
        String badNumber = "ABC123";
        String goodNumber = "423-867-5309";

        System.out.println("Testing Number " + badNumber);
        System.out.println("\t" + isValidNumber(badNumber));

        System.out.println("Testing Number " + goodNumber);
        System.out.println("\t" + isValidNumber(goodNumber));

    }

    private static boolean isValidNumber(String number) {
        String pattern = "(\\d-)?(\\d{3}-)?\\d{3}-\\d{4}";
        if(number.matches(pattern))
            return true;

        return false;
    }
}