# DeclareStructVar ## Description Declare a structure variable. IDA will ask you to choose a structure type. You must have some structure types defined in order to use this command. If the target assembler supports it, IDA will display the structure in terse form (using just one line). To uncollapse a terse structure variable use the Unhide command. You can also use this command to declare a structure field in another structure (i.e., nested structures are supported too). --- # 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.hex-rays.com/ida-actions/declarestructvar.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.