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Declarative programming is a programming paradigm that focuses on describing what should be accomplished rather than how it should be accomplished. In declarative programming, you define the desired result or outcome, and the underlying implementation details are abstracted away.
High-Level Abstractions: Declarative languages provide high-level abstractions that allow you to express complex operations and computations concisely. These abstractions are often closer to human-readable descriptions of the problem.
Focus on Relationships: Declarative programs emphasize relationships between different parts of the code rather than explicit sequences of steps. You specify relationships, patterns, and constraints that the system should adhere to.
Delegated Execution: The programming environment or runtime is responsible for executing the program efficiently. Developers do not need to manage low-level details of execution, like memory management or explicit control flow.
Implicit Control Flow: In declarative programming, control flow is often handled implicitly. The order of execution is determined by the relationships and dependencies between components rather than by explicit instructions.
Conciseness and Readability: Declarative code tends to be more concise and readable, as it focuses on expressing the intent of the code without getting bogged down in implementation details.
SQL (Structured Query Language): Used for querying and manipulating relational databases. You specify the data you want to retrieve or manipulate, and the database engine handles the actual retrieval and manipulation.
HTML (Hypertext Markup Language): Used for structuring and presenting web content. You define the structure of the content and its presentation, and the web browser renders it accordingly.
Regular Expressions: Used for pattern matching and manipulation of strings. You specify patterns that describe the desired text, and the regular expression engine handles the matching.
Functional Programming: While not exclusively declarative, functional programming often emphasizes immutability, higher-order functions, and expressing computations in terms of function compositions, which can lead to a more declarative style.
Declarative programming can lead to code that is easier to reason about, maintain, and extend, especially in complex and data-intensive applications. However, it may not be suitable for all types of problems and may require a programming environment or language that supports the declarative paradigm.
import java.util.stream.IntStream;
public class DeclarativeExample {
public static void main(String[] args) {
int sum = IntStream.rangeClosed(1, 10).sum();
System.out.println("Sum: " + sum);
}
}
In this example, we’re using Java’s Stream API to perform the summation
declaratively. The IntStream.rangeClosed(1, 10) generates a stream of integers from 1 to 10 (inclusive), and the sum() operation calculates the sum of those numbers. This code expresses the desired outcome (calculating the sum) without specifying the step-by-step process of how to achieve it, which is characteristic of declarative programming.
Declarative programming is a high-level programming concept, which is the opposite of imperative programming
Declarative programming relies on underlying components of a given language to carry out the necessary steps to reach the stated outcome. In declarative programming, typical programming constructs such as loops and if/then conditions do not exist, because they are instructional