8 regular expressions for very useful PHP

In Devolio.com the author made a list of 8 regurales expressions that considers equipment at the time of programming with PHP, many of them used to validate telephone names of user, numbers, directions of email among others.

To validate a user name

This rule is for allowing usuary of 4 up to 28 characters of length, alphanumeric and allowing low scripts.

$string = userNaME4234432_;
if (preg_match (/^ [a-z \ d_] {4.28} $/i, $string)) {
    I throw example 1 successful. ;
}

Telephone numbers
This is for validating telephone numbers (in the format of the United States, Canada and Mexico) the number must be of the following way: (###) ###-####

$string = (032) 555-5555;
if (preg_match (/^ (\ (? [0-9] {3.3} \)? |[0-9] {3.3} [-. ])[] [0-9] {3.3} [-. ]? [0-9] {4.4} $/, $string)) {
I throw successfully realised example 2. ;
}

The telephone number can be written (###) ###-#### thus, or thus ###-###-#### and also is going to validate.

Directions of email

It is not necessary to say plus the code is the following one.

$string = first.last@ domain.co.uk;
if (preg_match (
/^ [^0-9] [a-zA-Z0-9_]   ([.][a-zA-Z0-9_]  ) * [@] [a-zA-Z0-9_]   ([.][a-zA-Z0-9_]  ) * [.][a-zA-Z] {2.4} $/,
$string)) {
    I throw successfully realised example 3. ;
}

Postal codes

Postal codes of which it only allows numbers in following format xxxxx and xxxxx-xxxx

$string = 55324-4324;
if (preg_match (/^ [0-9] {5.5} ([-]? [0-9] {4.4})? $/, $string)) {
    I throw successfully realised example 4. ;
}

Directions IP

We did not need to do a PING nor nothing of the sort, we only verified that or they are written, how this 255.255.255.0 example.

$string = 255.255.255.0;
if (preg_match (
^ (: 25 [0-5]|2 [0-4] \ d|1 \ d \ d|[1-9] \ d|\ d) (: [.](: 25 [0-5]|2 [0-4] \ d|1 \ d \ d|[1-9] \ d|\ d)){3} $,
$string)) {
    I throw successfully realised example 5. ;
}

Hexadecimal colors

Since we also spoke of numbers we can verify hexadecimal values of numbers in its 2 forms the normal one and been brief (#333, 333, #333333 or 333333) with the optional symbol #.

$string = #666666;
if (preg_match (/^# (: (: [high frequency \ d] {3}) {1.2}) $/i, $string)) {
    I throw successfully realised example 6. ;
}

To look for commentaries multi-line

A form simple to look for or to eliminate commentaries multiline in PHP/CSS/Otros languages.

$string = /* commmmment *;
if (preg_match (/^ [(/*)  ,  (*)]$/, $string)) {
    I throw successfully realised example 7. ;
}

Dates
One of the typical formats of dates is the MM/DD/YYYY and its validation is the following one.

$string = 10/15/2007;
if (preg_match (/^ \ d {1.2} \/\ d {1.2} \/\ d {4} $/, $string)) {
    I throw successfully realised example 8. ;
}

You know some other expression regular that useful?