Perl and PHP Regular Expressions |

PHP regexes are based on the PCRE (Perl-Compatible Regular Expressions), so any regexp that works for one should be compatible with the other or any other language that makes use of the PCRE format. Here are some commonly needed regular expressions for both PHP and Perl. Each regex will be in string format and will include delimiters.

All Major Credit Cards

This regular expression will validate all major credit cards: American Express (Amex), Discover, Mastercard, and Visa.

//All major credit cards regex
'/^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6011[0-9]{12}|622((12[6-9]|1[3-9][0-9])|([2-8][0-9][0-9])|(9(([0-1][0-9])|(2[0-5]))))[0-9]{10}|64[4-9][0-9]{13}|65[0-9]{14}|3(?:0[0-5]|[68][0-9])[0-9]{11}|3[47][0-9]{13})*$/'

//All major credit cards regex
‘/^(?:4[0-9]{12}(?:[0-9]{3})?|5[1-5][0-9]{14}|6011[0-9]{12}|622((12[6-9]|1[3-9][0-9])|([2-8][0-9][0-9])|(9(([0-1][0-9])|(2[0-5]))))[0-9]{10}|64[4-9][0-9]{13}|65[0-9]{14}|3(?:0[0-5]|[68][0-9])[0-9]{11}|3[47][0-9]{13})*$/’

Alpha-Numeric Characters

Test for alpha-numeric characters with this regexp.

//Alpha-numeric characters only
'/^[a-zA-Z0-9]*$/'

//Alpha-numeric characters only
‘/^[a-zA-Z0-9]*$/’

Alpha-Numeric Characters With Spaces

Test for alpha-numeric characters and spaces with this regexp.

//Alpha-numeric characters with spaces only
'/^[a-zA-Z0-9 ]*$/'

//Alpha-numeric characters with spaces only
‘/^[a-zA-Z0-9 ]*$/’

Alphabetic Characters

This regex will test for alphabetic characters only (upper and lowercase).

//Alphabetic characters only
'/^[a-zA-Z]*$/'

//Alphabetic characters only
‘/^[a-zA-Z]*$/’

American Express Credit Card

Verify Amex credit cards with this regexp.

//Amex credit card regex
'/^(3[47][0-9]{13})*$/'

//Amex credit card regex
‘/^(3[47][0-9]{13})*$/’

Australian Postal Codes

If you need to verify Australian Postal Codes, use this regular expression.

//Australian Postal Codes
'/^((0[289][0-9]{2})|([1345689][0-9]{3})|(2[0-8][0-9]{2})|(290[0-9])|(291[0-4])|(7[0-4][0-9]{2})|(7[8-9][0-9]{2}))*$/'

//Australian Postal Codes
‘/^((0[289][0-9]{2})|([1345689][0-9]{3})|(2[0-8][0-9]{2})|(290[0-9])|(291[0-4])|(7[0-4][0-9]{2})|(7[8-9][0-9]{2}))*$/’

Canadian Postal Codes

Tests for valid Canadian Postal Codes.

//Canadian Postal Codes
'/^([ABCEGHJKLMNPRSTVXY][0-9][A-Z] [0-9][A-Z][0-9])*$/'

//Canadian Postal Codes
‘/^([ABCEGHJKLMNPRSTVXY][0-9][A-Z] [0-9][A-Z][0-9])*$/’

Canadian Provinces

Evaluate Canadian province abbreviations with this regular expression.

//Canadian Province Abbreviations
'/^(?:AB|BC|MB|N[BLTSU]|ON|PE|QC|SK|YT)*$/'

//Canadian Province Abbreviations
‘/^(?:AB|BC|MB|N[BLTSU]|ON|PE|QC|SK|YT)*$/’

Date (MM/DD/YYYY)

Validate the calendar date in MM/DD/YYYY format with this regex. Optional separators are spaces, hyphens, forward slashes, and periods. The year is limited between 1900 and 2099.

//Date (MM/DD/YYYY)
'/^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$/'

//Date (MM/DD/YYYY)
‘/^((0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01])[- /.](19|20)?[0-9]{2})*$/’

Date (YYYY/MM/DD)

Validate the calendar date in YYYY/MM/DD format with this regex. Optional separators are spaces, hyphens, forward slashes, and periods. The year is limited between 1900 and 2099.

//Date (YYYY/MM/DD)
'#^((19|20)?[0-9]{2}[- /.](0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01]))*$#'

//Date (YYYY/MM/DD)
‘#^((19|20)?[0-9]{2}[- /.](0?[1-9]|1[012])[- /.](0?[1-9]|[12][0-9]|3[01]))*$#’

Digits

This regex will test for digits (whole numbers).

//Digits only
'/^[0-9]*$/'

//Digits only
‘/^[0-9]*$/’

Diner’s Club Credit Card

Test and verify Diner’s Club credit card numbers with this regexp.

//Diner's Club credit card regex
'/^(3(?:0[0-5]|[68][0-9])[0-9]{11})*$/'

//Diner’s Club credit card regex
‘/^(3(?:0[0-5]|[68][0-9])[0-9]{11})*$/’

Emails

This email regex is not fully RFC5322-compliant, but it will validate most common email address formats correctly.

//Email regex
'/^([a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})*$/'

//Email regex
‘/^([a-zA-Z0-9._%-]+@[a-zA-Z0-9.-]+\.[a-zA-Z]{2,4})*$/’

IP Addresses

Test IP Addresses with this regular expression.

//IP address regex
'/^((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))*$/'

//IP address regex
‘/^((?:(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?)\.){3}(?:25[0-5]|2[0-4][0-9]|[01]?[0-9][0-9]?))*$/’

Lowercase Alphabetic Characters

This regex will test for lowercase letters.

//Lowercase letters only
'/^([a-z])*$/'

//Lowercase letters only
‘/^([a-z])*$/’

MasterCard Credit Card

Verify MasterCard credit card numbers with this regex.

//MasterCard credit card numbers
'/^(5[1-5][0-9]{14})*$/'

//MasterCard credit card numbers
‘/^(5[1-5][0-9]{14})*$/’

Passwords

Test for a strong password with this regex. The password must contain one lowercase letter, one uppercase letter, one number, and be at least 6 characters long.

//Password regex
'/^(?=^.{6,}$)((?=.*[A-Za-z0-9])(?=.*[A-Z])(?=.*[a-z]))^.*$/'

//Password regex
‘/^(?=^.{6,}$)((?=.*[A-Za-z0-9])(?=.*[A-Z])(?=.*[a-z]))^.*$/’

Phone Numbers (North American)

This regex will validate a 10-digit North American telephone number. Separators are not required, but can include spaces, hyphens, or periods. Parentheses around the area code are also optional.

//Phone number regex
'/^((([0-9]{1})*[- .(]*([0-9]{3})[- .)]*[0-9]{3}[- .]*[0-9]{4})+)*$/'

//Phone number regex
‘/^((([0-9]{1})*[- .(]*([0-9]{3})[- .)]*[0-9]{3}[- .]*[0-9]{4})+)*$/’

Social Security Numbers

If you need to validate US Social Security Numbers, use this regular expression

//SSN regex
'/^([0-9]{3}[-]*[0-9]{2}[-]*[0-9]{4})*$/'

//SSN regex
‘/^([0-9]{3}[-]*[0-9]{2}[-]*[0-9]{4})*$/’

UK Postal Codes

This regexp verifies UK Postal Codes.

//UK Postal Codes regex
'/^([A-Z]{1,2}[0-9][A-Z0-9]? [0-9][ABD-HJLNP-UW-Z]{2})*$/'

//UK Postal Codes regex
‘/^([A-Z]{1,2}[0-9][A-Z0-9]? [0-9][ABD-HJLNP-UW-Z]{2})*$/’

Uppercase Alphabetic Characters

This regex will test for uppercase letters.

//Uppercase letters only
'/^([A-Z])*$/'

//Uppercase letters only
‘/^([A-Z])*$/’

URLs

This URL regex will validate most common URL formats correctly.

//URL regex
'/^(((http|https|ftp):\/\/)?([[a-zA-Z0-9]\-\.])+(\.)([[a-zA-Z0-9]]){2,4}([[a-zA-Z0-9]\/+=%&_\.~?\-]*))*$/'

//URL regex
‘/^(((http|https|ftp):\/\/)?([[a-zA-Z0-9]\-\.])+(\.)([[a-zA-Z0-9]]){2,4}([[a-zA-Z0-9]\/+=%&_\.~?\-]*))*$/’

US States

Validate all 2-letter US State abbreviates with this regular expression.

//US States regex
'/^(?:A[KLRZ]|C[AOT]|D[CE]|FL|GA|HI|I[ADLN]|K[SY]|LA|M[ADEINOST]|N[CDEHJMVY]|O[HKR]|PA|RI|S[CD]|T[NX]|UT|V[AT]|W[AIVY])*$/'

//US States regex
‘/^(?:A[KLRZ]|C[AOT]|D[CE]|FL|GA|HI|I[ADLN]|K[SY]|LA|M[ADEINOST]|N[CDEHJMVY]|O[HKR]|PA|RI|S[CD]|T[NX]|UT|V[AT]|W[AIVY])*$/’

US ZIP Codes

This regexp verifies US ZIP Codes, with an optional 4 number ZIP code extension.

//US ZIP Codes regex
'/^([0-9]{5}(?:-[0-9]{4})?)*$/'

//US ZIP Codes regex
‘/^([0-9]{5}(?:-[0-9]{4})?)*$/’

Visa Credit Card

Verify Visa credit card numbers with this regex.

//Visa credit card numbers
'/^(4[0-9]{12}(?:[0-9]{3})?)*$/'

//Visa credit card numbers
‘/^(4[0-9]{12}(?:[0-9]{3})?)*$/’

JavaScript Regular Expressions

The JavaScript version of regex is a slightly different flavor than the PCRE variety, so I’ve included those regexes in a separate section.