Added phone number validation in PHP

CONTRIBUTORS.md

@@ -82,3 +82,8 @@ Programming Language: Java, C, HTML, CSS, Kotlin
 Email: [email protected]
 
 
+Name: [John Braun](https://github.com/jhnbrn90)  
+About: I am doing a PhD in organic chemistry and really like programming. Used Laravel to create some useful tools for our research group, amongst others a chemicals inventory, booking system and supporting information manager.
+Programming Language: PHP, JavaScript
+Email: [email protected]
+

telephone-validator/validator.php

@@ -0,0 +1,44 @@
+<?php
+
+/**
+** Phone number validator
+** based on the JS validator regex.
+** In this example, 2-123-123-1231 will return true
+*/
+
+class PhoneNumber
+{
+    protected $phoneNumber;
+
+    protected $regex = '/^\d(?:-\d{3}){3}\d$/';
+
+    /**
+     * PhoneNumber constructor.
+     * @param $phoneNumber
+     */
+    public function __construct($phoneNumber)
+    {
+        $this->phoneNumber = $phoneNumber;
+    }
+
+    /**
+     * Validate the passed in phone number
+     * using the defined regex
+     * @return bool
+     */
+    public function validate()
+    {
+        preg_match($this->regex, $this->phoneNumber, $matches);
+        return !empty($matches);
+    }
+}
+
+// Register a new phone number
+$phoneNumber = new PhoneNumber('2-123-123-1231');
+
+// validate the phone number, returning a boolean
+$phoneNumber->validate();
+
+// return a statement (string) based on the boolean value
+echo $phoneNumber->validate() ? 'Valid phone number :-)' : 'Invalid phone number :-(';
+