此RegEx仅适用于8位数的电话号码，如何使其适用于15位数？

Question

Someone in Stack Overflow gave me this code:

$output = preg_replace( '/(\+?\d{2}|0)(\d{7,8})/', '0$2', $test);

It changes user input:

[phone] into 02112345

622112345 into 02112345

02112345 into 02112345

Unfortunately it only works for 7-8 digits. I decided to change the code into this:

$output = preg_replace( '/(\+?\d{2}|0)(\d{15})/', '0$2', $test);

By changing (\d{7,8}) into (\d{15}), I hoped I could get this RegEx to validate up to 15 digits. But, here's what I have:

input : 083812345678910 >> output : 083812345678910 [correct]

input : 6283812345678910 >> output : 6283812345678910 [false, should be : 083812345678910]

input : +6283812345678910 >> output : 6283812345678910 [false, should be : 083812345678910]

How can I make this works on 15 digit numbers? Thanks.

UPDATE : user input can be 10, 11, 12 or even 13 digits. but not more than 15 digits. so I need this code to change the prefix : either +62, 62 or 0 INTO 0xxxx. no matter how many digits they have, 15 maximum.

Answer 1

The correct regex is:

$output = preg_replace( '/(0|\+?\d{2})(\d{7,14})/', '0$2', $test);

Even though you have 16 digit numbers, there should only be at most 14 digits after the extension, to account for the 2 digit extension. Note that this will work for more extensions other than 62, if this is not desired, replace \d{2} with 62.

Demo