YAGNI: принцип Keep It Simple

YAGNI (You Ain't Gonna Need It) - is a software development principle that involves avoiding the implementation of functionality that is not currently needed. It emphasizes minimalism, avoiding unnecessary complexity and redundancy in the code. By applying the YAGNI principle, developers strive to create only the functions that are necessary for current user or business requirements, and postpone the implementation of future functions until they are actually needed.

Applying the YAGNI principle helps keep the code simple for understanding, testing, and maintenance. Developers, by following this principle, do not waste time and resources on developing unnecessary functionality, which leads to increased efficiency and reduced development costs.

Here are examples of code illustrating the YAGNI principle:

1. Code without applying the YAGNI principle:

public class Calculator {
    public int sum(int a, int b) {
        return a + b;
    }
    
    public int multiply(int a, int b) {
        return a * b;
    }
    
    public int subtract(int a, int b) {
        return a - b;
    }
    
    public int divide(int a, int b) {
        return a / b;
    }
    
    public int square(int a) {
        return a * a;
    }
}

In this example, we have a Calculator class that has a set of arithmetic operations, including addition, multiplication, subtraction, division, and squaring. However, it is possible that not all of these operations are necessary at the moment. By applying the YAGNI principle, we can optimize the code by removing operations that are not currently required.

2. Code with the application of the YAGNI principle:

public class Calculator {
    public int sum(int a, int b) {
        return a + b;
    }
}

In this example, we apply the YAGNI principle by implementing only the addition operation. In doing so, we avoid unnecessary complexity and redundancy in the code.

The YAGNI principle is also applicable to creating objects, methods, classes, and even microservices. The goal is to avoid unnecessary features that may only arise as a result of assumptions about future requirements. This allows us to focus on current tasks and make the most of resources for developing the functionality that is truly necessary.

In conclusion, the YAGNI principle is a useful guideline for software development that helps avoid unnecessary complexity and redundancy. By following this principle, developers create only the functionality that is necessary at the current moment, postponing the implementation of possible future functions until they are actually needed. This contributes to the creation of more efficient and readable code, as well as saving time and resources in development.