Use cases in Java

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Introduction

Use cases help us understand what a program or system should do. They show how users interact with the program step-by-step.

When planning a new program to know what features to build.

When explaining to others how the program works.

When testing the program to check if it meets user needs.

When fixing problems by understanding how users use the program.

When designing user-friendly software.

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Syntax

Java

Use cases are usually written as simple steps or stories, not code. For example:

1. User logs in.
2. User selects an item.
3. User checks out.

In Java, you implement these steps with methods and classes.

Use cases are written in plain language, easy to understand.

They focus on user actions and program responses.

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Examples

line_end_arrow_notchThis shows a simple login use case as steps.

Java

Use Case: Login
1. User enters username and password.
2. System checks credentials.
3. System allows access if correct.

line_end_arrow_notchThis describes how a user adds an item in an online store.

Java

Use Case: Add Item to Cart
1. User selects product.
2. User clicks 'Add to Cart'.
3. System adds product to shopping cart.

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Sample Program

This Java program prints the steps of a simple login use case. It shows how use cases can be represented in code as output.

Java

public class UseCaseExample {
    public static void main(String[] args) {
        System.out.println("Use Case: Login");
        System.out.println("Step 1: User enters username and password.");
        System.out.println("Step 2: System checks credentials.");
        System.out.println("Step 3: System allows access if correct.");
    }
}

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Important Notes

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Use cases are not code but help guide coding.

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They make it easier to understand what the program should do.

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Always write use cases in simple language anyone can understand.

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Summary

Use cases describe how users interact with a program.

They help plan, explain, and test software.

Use cases are written as simple steps or stories.