<?php

error_reporting(-1);

$correctNumbers = [ 
  '84951234567',  '+74951234567', '8-495-1-234-567', 
  ' 8 (8122) 56-56-56', '8-911-1234567', '8 (911) 12 345 67', 
  '8-911 12 345 67', '8 (911) - 123 - 45 - 67', '+ 7 999 123 4567', 
  '8 ( 999 ) 1234567', '8 999 123 4567'
];
$incorrectNumbers = [
  '02', '84951234567 позвать люсю', '849512345', '849512345678', 
  '8 (409) 123-123-123', '7900123467', '5005005001', '8888-8888-88',
  '84951a234567', '8495123456a', 
  '+1 234 5678901', /* неверный код страны */
  '+8 234 5678901', /* либо 8 либо +7 */
  '7 234 5678901' /* нет + */
];

$regexp = '/^(( ?[+] ?7)| ?8)( *[(]? *-? *\d *-? *[)]? *){10}$/u';
foreach ($correctNumbers as $phoneNumber) {
	echo "{$phoneNumber} -";
	if (preg_match($regexp, $phoneNumber)) {
		echo " Correct\n";
	} else{
		echo " Incorrect\n";
	}
};
foreach ($incorrectNumbers as $phoneNumber) {
	echo "{$phoneNumber} -";
	if (preg_match($regexp, $phoneNumber)) {
		echo " Correct\n";
	} else{
		echo " Incorrect\n";
	}
};