# General concepts ### ⚠ The warning sign indicates the element is **not** **available**. ### ★ The element starred as most **useful**. ### **Checks** It's to **check** the provided value to be the same as **expected**. ### Type guard (constrain) Constrains the parameter type to not let input unexpected value in the code editor. ### **Guard** It's a **combination** of both above, **constrains** the type of the parameter in the **code editor**, and checks its provided argument. ### **Defines** Returns defined value from a method of an object. Defines new value in an object and returns a defined value. ### **Gets** Returns a value from an object. ### **Sets** Adds or updates an element with a specified key and a value to an object and returns an object. ### Intuitive Having the ability to know or understand things without any proof or evidence. E.g. some of the accessor names indicate directly its role. ### General Relating to the main or major parts of something rather than the details. E.g. some of the accessor names don't indicate the specific role in the object. {% embed url="" %} More definitions {% endembed %} --- # 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.angular-package.dev/error/general-concepts.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.