Easily Understanding Lifecycles in Programming
Tags: react, angular, frontend, backend
Published: 2024-05-27 10:37:20

In the world of programming, every application follows a specific journey from its creation to its closure. This journey, often termed as a "lifecycle," is fundamental for developers. But what does this really mean? Let me explain to you in a simple and concrete manner.

#### **What is a Lifecycle?**

Imagine your application as a living organism that traverses different phases of its life, from birth to death. Each phase or lifecycle represents a crucial moment in the operation of your application. These moments are triggered by events like the application's launch, user interaction, or its closure.

#### **Why Do We Use Lifecycles?**

Lifecycles are used to manage the behavior of the application at various points during its execution. They allow developers to take specific actions at each step, such as initializing variables, loading data, or cleaning up resources. In summary, lifecycles provide a structure for organizing code and ensuring that the application functions correctly in all situations.

**Illustration**

Imagine you're building a house. You have key stages like the foundation, walls, roof, etc. Each stage requires specific actions to progress to the next. Lifecycles work similarly for an application, ensuring that each phase of its execution is properly managed.

#### **What Problems Do Lifecycles Solve?**

Without lifecycles, managing the different situations an application may encounter would be complicated. For example, what happens when the user closes the application or interacts with a form? Lifecycles offer entry points to execute the necessary code for each event, effectively addressing these questions.

#### **Some Frameworks That Use Lifecycles**

Many modern frameworks simplify the development process by using lifecycles. Whether it's a frontend or backend framework, the operating principle is almost the same. But let's focus on frontend frameworks.

#### **Practical Examples of Lifecycles**

1. **During Application Creation**

- **React**: Use the `useState` hook to prepare initial variables.
```jsx
    const [state, setState] = useState(initialState);
```

- **Angular**: Angular uses the constructor to define initial variables, then `ngOnInit` to prepare variables, for example, during component initialization.
```typescript
    constructor() {
        this.variable = initialValue;
    }
    
    ngOnInit() {
        // Load data from a server
    }
```

2. **After Application Creation: Initializing Interactions**

- **React**: Use `useEffect` to inject variables and initialize interactions after component rendering.
```jsx
    useEffect(() => {
        // Initialize interactions
    }, []);
```

- **Angular**: Use `ngAfterViewInit` to manipulate DOM elements after HTML content is ready.
```typescript
    ngAfterViewInit() {
        // Manipulate DOM elements
    }
```

3. **When Content Changes**
- **React**: `useEffect` can be used with a dependency to react to content changes.
```jsx
    useEffect(() => {
        // React to content changes
    }, [content]);
```

- **Angular**: `ngOnChanges` can be used to handle changes in component-bound properties.
```typescript
    ngOnChanges(changes: SimpleChanges) {
        if (changes['content']) {
            // React to content changes
        }
    }
```

It's important to consult the documentation of these frameworks to better understand how to use them.

#### **Conclusion**

Lifecycles are an essential tool for every developer, allowing for effective management of an application's lifecycle and ensuring a consistent user experience. By understanding and applying these fundamental concepts, developers can build robust and reliable applications, ready to tackle the challenges of the ever-evolving digital world.

With lifecycles, you can transform a simple application into an exceptional user experience, managing each stage in a structured and efficient manner. Embark on this journey and discover how lifecycles can revolutionize your approach to application development.

In the next article, we'll explore how to use lifecycles according to developers' needs in three major frameworks. Subscribe to stay updated!

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