Declarative

Declarative refers to a style of writing or programming that expresses what outcome is desired without specifying the precise steps to achieve it. It emphasizes describing the 'what' rather than the 'how.' In linguistics, a declarative sentence is one that makes a statement. This approach is often contrasted with imperative styles, which focus on providing explicit instructions. The goal is to create clear, concise, and easily understandable representations of information or desired results, leaving the implementation details to the underlying system or software.

Declarative meaning with examples

• The SQL query, 'SELECT * FROM customers WHERE city = 'London'', is a declarative statement. It tells the database *what* data is needed, but not *how* to retrieve it. The database engine determines the most efficient method. This contrasts with imperative methods which would specify the exact steps needed for retrieval.
• When describing a website, a declarative approach uses HTML to define the structure of the page. It specifies the elements like headings and paragraphs. The browser renders them in a declarative style, based on CSS for formatting. This way you define the outcome, not the steps.
• In a state management library, a declarative approach to updating the user interface focuses on describing how the UI should look based on the application's current state. The library automatically updates the UI to reflect changes. This contrast with manually changing aspects.
• The following code is declarative: 'Given the customer wants to purchase a laptop and the price is 1000. Then create the purchase order.' This code describes the desired outcome of the program.