# Examples Suppose your input field contains a text value like `"Author, Ann" - 53 posts`. The following regular expression creates four capturing groups and can be used to parse out the different parts: ``` ^"((["]), (["]))" - (\d+) posts\.$ ``` This expression creates the following four capturing groups, which become output fields: * Fullname: `((["]), (["]))` * Lastname: `([^"]+)` * Firstname: `([^"]+)` * Number of posts: `(\d+)` In this example, a field definition must be present for each of these capturing groups. If the number of capture groups in the regular expression does not match the number of fields specified, the step will fail and an error is written to the log. Capturing groups can be nested. In the example above the fields **Lastname** and **Firstname** correspond to the capturing groups that are themselves contained inside the **Fullname** capturing group. The `design-tools/data-integration/samples/transformations` directory contains the `samples/transformations/Regex Eval - parse NCSA access log records.ktr` as another example on how to use this step. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.pentaho.com/pdia-data-integration/10.2-data-integration/pdi-transformation-steps-reference-overview/regex-evaluation/examples.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.