<?php
$number = '+7 (905) 821-35-21'; // пользователь прислал номер
$patterns[0] = '/[-\s()]*/';
$patterns[1] = '/\+7/';
$replacements[2] = '';
$replacements[1] = '8';
$yesOrNot = preg_match('/^(\+\s?7|8)([-\s()]*\d){10}$/', $number, $matches); // проверяем корректность if ($yesOrNot) {
echo "если условие выполнилось видимо номер верен \n";
// очищаем от тире, пробелов и скобок и заменяем +7 на 8
}
echo $number;
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