# Regular expression (Glossary)

Regular expressions are a way to describe what a series of characters should look like. For example a zipcode of a phone number. In FBO One regular expressions are used in the configuration for certain fields.

Regular expressions are not easy to understand, we'll be glad to help you change them if you need to. Some examples of regular expressions are listed below:

```dutch zipcode (eg 1016GL)

\d\d\d\d\s?[a-zA-Z]{2}

note: this will accept zipcodes with and without space, and also illegal zipcodes like 9999XX```
```dutch phonenumber (10 digits, may be with spaces and a dash)

([0-9][ \-\.]*?){10}

note: this is not perfect, but usually close enough.```
```number starting with 1, then 8 digits

^1[0-9]{8}\$
```
```text of max 8 characters

^\w{0,8}\$```
```number of 7 or 8 characters

^\d{7,8}\$```
Date Format dd/mm/yyyy (e.g. 31/12/2018)
`^([0-2][0-9]|(3)[0-1])(\/)(((0)[0-9])|((1)[0-2]))(\/)\d{4}\$`
```Date and time format dd-MMM-yy hh:mm format

^([1-9]|([012][0-9])|(3[01]))-(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|Dec)-\d\d [012]{0,1}[0-9]:[0-6][0-9]\$```
```Time format HH:mm

^([01]?[0-9]|2[0-3]):[0-5][0-9]```
```Max 2 digits with 1 decimal point eg 25.2

^\d{1,2}(?:\.\d)?\$```
```Max 3 digits with 1 decimal point eg 215.2

^\d{1,3}(?:\.\d)?\$```

#### More information

http://en.wikipedia.org/wiki/Regular_expression

http://www.regular-expressions.info/

https://regex101.com/