# Masked Input Using Regular Expressions

Learn how to use Masked Input Using Regular Expressions for validating complex input formats.

## Content

You can use regular expressions in masks for validating more complex input formats using [RegexpEditMask](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.MaskInfo.RegexpEditMask.html) of [MaskInfo](/componentone/api/win/online-input/dotnet-framework-api/C1.Win.C1Input.4.8/C1.Win.C1Input.MaskInfo.html) class. The Properties pane showing **RegexpEditMask** property for **c1TextBox** control is as shown:

![regexmask](https://cdn.mescius.io/document-site-files/images/6c2f30e9-4d3a-4f86-b649-ecbef777b3a3/documentsimagestbh/maskinfo_regexpeditmask.png)

The keywords in regular expressions and their description is shown in the following table:

| Keywords | Description |
| -------- | ----------- |
| \\A | Matches any upper case alphabet [A-Z]. |
| \\a | Matches any lower case alphabet [a-z]. |
| \\D | Matches any decimal digit [0-9]. |
| \\W | Matches any word character. It is same as [a-z A-Z 0-9]. |
| \\K | Matches SBCS Katakana. |
| \\H | Matches all SBCS characters. |
| \\ A | Matches any upper case DBCS alphabet [A-Z]. |
| \\ a | Matches any lower case DBCS alphabet [a-z]. |
| \\ D | Matches any DBCS decimal digit [0-9]. |
| \\ W | Matches any DBCS word character. It is same as [a-z A-Z 0-9]. |
| \\ K | Matches all DBCS Katakana. |
| \\ J | Matches all Hiragana. |
| \\ Z | Matches all DBCS characters. |
| \\N | Matches all SBCS big Katakana. |
| \\ N | Matches all DBCS big Katakana. |
| \\ G | Matches DBCS big Hiragana. |
| \\ T | Matches surrogate character. |
| [] | Matches a character subset. |
| [^] | To express an exclude subset. |
| - | Defines contiguous character range. |
| {} | Specifies the number of times to match. |
| \* | Specifies zero or more matches. It is the short expression for {0,}. |
| + | Specifies one or more matches. It is the short expression for {1,}. |
| ? | Specifies zero or one matches. It is the short expression for {0,1}. |