Format 10-digit string into hyphenated phone number

Question

I have a string containing a ten-digit phone number and I want to format it with hyphens.

I am seeking a way to convert 123456790 to 123-456-7890 as phone numbers are typically formatted in the USA.

Answer 1

$areacode = substr($phone, 0, 3);
$prefix   = substr($phone, 3, 3);
$number   = substr($phone, 6, 4);

echo "$areacode-$prefix-$number";

You could also do it with regular expressions:

preg_match("/(\d{3})(\d{3})(\d{4})/",$phone,$matches);
echo "$matches[1]-$matches[2]-$matches[3]";

There are more ways, but either will work.