Regular Expressions and some useful Examples.

Regular Expressions

Manytimes, while creating a regular expression in Real Testing Environment, we face some problems. Here, I have ried to extract out regular expressions, which we can apply directly as it is. Some of these scenarios are:

Pattern for Password

 Pattern: [a-zA-Z]\w{3,14}

 Matching Text: abcd, aBc45DSD_sdf, password

 Non-Matching Text afv, 1234, reallylongpassword

The password's first character must be a letter, it must contain at least 4 characters and no more than 15 characters and no characters other than letters, numbers and the underscore may be used.

Pattern for IP Address

 Pattern: \d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}

 Matching Text:  match any IP address just fine, but will also match 999.999.999.999 as if it were a valid IP address.

Pattern for Visa Credit Card

 Pattern: ([4]{1})([0-9]{12,15})

 Matching Text: 4125632152365, 418563256985214, 4125632569856321

 Non-Matching Text: 3125652365214, 41256321256, 42563985632156322

Validate against a visa card number. All visa cards start with a 4 and are followed by 12 to 15 more numbers.

Title Alphanumeric

 Pattern: [a-zA-Z0-9]+$

 Matching Text: 10a, ABC, A3fg

 Non-Matching Text: 45.3, this or that, $23

Matches any alphanumeric string (no spaces).

Pattern for Six Integer Indian ZIP Code

 Pattern \d{6}

 Matching Text: 333333, 555555, 234455

 Non-Matching: Text abcd, 1324, as;lkjdf

Matches 6 numeric digits, such as a zip code.

Pattern for Indian Currency

 Pattern: \INR(\d{1,3}(\,\d{3})*|(\d+))(\.\d{2})?

 Matching Text: INR0.84, INR123458, INR1,234,567.89

 Non-Matching Text: 12345, 1.234INR

This matches Indian currency format with INR as Ruppee sign. INR value must have at least one digit and may or may not be comma separated. Paisa value is optional.

 Matching a Valid Date

19|20)\d\d[- /.](0[1-9]|1[012])[- /.](0[1-9]|[12][0-9]|3[01]) matches a date in yyyy-mm-dd format from between 1900-01-01 and 2099-12-31, with a choice of four separators. The year is matched by (19|20)\d\d.