Php 将电话号码格式转换为普通号码

我有一些电话格式的变量，如以下变量：

$phone1 = "(123) 123-1234";
$phone2 = "+1234567892";
$phone3 = "123-434-3432

$new_phone1 = "1231231234";
$new_phone2 = "1234567892";
$new_phone3 = "1234343432";

如何在php中将这些变量转换为纯数字

结果应类似于以下变量：

$phone1 = "(123) 123-1234";
$phone2 = "+1234567892";
$phone3 = "123-434-3432

$new_phone1 = "1231231234";
$new_phone2 = "1234567892";
$new_phone3 = "1234343432";

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使用preg_replace，它使用正则表达式

preg_替换（“/[^0-9]/”、“，'123-434-3432”）

删除除数字以外的所有内容