Modern Javascript Patterns

---
name: modern-javascript-patterns
description: Master ES6+ features including async/await, destructuring, spread operators, arrow functions, promises, modules, iterators, generators, and functional programming patterns for writing clean, efficient JavaScript code. Use when refactoring legacy code, implementing modern patterns, or optimizing JavaScript applications.
category: development-code
version: 1.0.0
---

# Modern JavaScript Patterns

Comprehensive guide for mastering modern JavaScript (ES6+) features, functional programming patterns, and best practices for writing clean, maintainable, and performant code.

## When to Use This Skill

- Refactoring legacy JavaScript to modern syntax
- Implementing functional programming patterns
- Optimizing JavaScript performance
- Writing maintainable and readable code
- Working with asynchronous operations
- Building modern web applications
- Migrating from callbacks to Promises/async-await
- Implementing data transformation pipelines

## Detailed patterns and worked examples

Detailed pattern documentation lives in `references/details.md`. Read that file when the navigation tier above is insufficient.

## Best Practices

1. **Use const by default**: Only use let when reassignment is needed
2. **Prefer arrow functions**: Especially for callbacks
3. **Use template literals**: Instead of string concatenation
4. **Destructure objects and arrays**: For cleaner code
5. **Use async/await**: Instead of Promise chains
6. **Avoid mutating data**: Use spread operator and array methods
7. **Use optional chaining**: Prevent "Cannot read property of undefined"
8. **Use nullish coalescing**: For default values
9. **Prefer array methods**: Over traditional loops
10. **Use modules**: For better code organization
11. **Write pure functions**: Easier to test and reason about
12. **Use meaningful variable names**: Self-documenting code
13. **Keep functions small**: Single responsibility principle
14. **Handle errors properly**: Use try/catch with async/await
15. **Use strict mode**: `'use strict'` for better error catching

For common pitfalls (this binding, promise anti-patterns, memory leaks), see [references/advanced-patterns.md](references/advanced-patterns.md).