Regular Expressions provide the foundation for describing or matching data according to defined syntax rules. A Regular Expression is nothing more than a pattern of characters itself, matched against a certain parcel of text. Using Regular Expressions, it is simple to search for a specific word or string of characters. Almost every editor on every computer system can do this. Regular expressions are more powerful and flexible. You can search for words of a certain size. You can search Numbers, punctuation characters, patterns and so on.At the same time, Regular Expression can be very confusing and tricky. The learning curve for Regular expression may not be very easy for everyone. Often this results in to underutilization of Regular Expression and true power is not harnessed.The mapping sample given here exemplifies the power of Regular Expressions by identifying valid E-mail addresses. In the given example, the input data can have E-mail addresses in multiple yet valid formats. The mapping logic should be able to identify all the valid values. Download file also contains a detailed PowerPoint presentation describing functionality and parameters of Regular Expression functions.You can download this listing as part of the Bundle : Regular Expression.