101 Guide to JavaScript

A comprehensive collection of 81 JavaScript tips and examples to level up your skills, from beginner basics to advanced mastery. Each tip is a small, focused example you can read, run, and learn from.

📚 Structure

The tips are organized into 8 chapters with increasing complexity:

1. Introduction – Beginner-friendly basics (Tips 0-10)
2. Fundamentals – Core concepts and foundations (Tips 11-20)
3. Intermediate – More complex topics and common patterns (Tips 21-29)
4. Advanced – Deep dives and advanced techniques (Tips 30-40)
5. Modern Features – ES6+ features and async patterns (Tips 41-50)
6. Performance – Optimization and efficient code (Tips 51-60)
7. Expert – Expert-level concepts and cutting-edge features (Tips 61-70)
8. Masterclass – Advanced problem solving and modern APIs (Tips 71-80)

Each file contains:

• Clear explanation of the concept
• Runnable code examples with detailed comments
• Practical use cases showing real-world applications

📖 Complete Tip List

1. Introduction (Tips 0-10)

0. Strict Mode - Enable strict mode for safer code
1. Const vs Let - Use const and let instead of var
2. Template Literals - String interpolation with backticks
3. Default Parameters - Set default function parameter values
4. Destructuring Assignment - Extract object properties
5. Spread Operator - Clone and merge arrays/objects
6. Arrow Functions - Concise function syntax
7. Short-Circuit Evaluation - Use && and || for conditional logic
8. Optional Chaining - Safely access nested properties with ?.
9. Nullish Coalescing - Use ?? to handle only null or undefined
10. Array.map() - Transform arrays with map()

2. Fundamentals (Tips 11-20)

11. Falsy vs Truthy Values - Understanding truthy and falsy values
12. Ternary Operator - Conditional assignment with ternary operator
13. Object Property Shorthand - Concise object property syntax
14. Array Destructuring - Extract array values with destructuring
15. Rest Operator - Collect multiple arguments with rest operator
16. Default Object Destructuring - Set default values in object destructuring
17. Array.filter() - Filter array elements with filter()
18. Array.reduce() - Reduce arrays to single values
19. Array.find() - Find first matching element
20. Array.some() and Array.every() - Test array elements

3. Intermediate (Tips 21-29)

21. Array.includes() - Check array membership with includes()
22. String Methods - String analysis with startsWith, endsWith, includes
23. Sets - Store unique values with Set
24. Maps - Key-value storage with Map
25. Object Methods - Extract object data with keys, values, entries
26. Dates - Work with dates and times
27. Error Handling - Handle errors with try-catch-finally
28. Custom Errors - Create custom error classes
29. Array.flat() and flatMap() - Flatten nested arrays

4. Advanced (Tips 30-40)

30. Regular Expressions - Pattern matching with regex
31. String Padding - Pad strings with padStart() and padEnd()
32. Array.from() - Create arrays from iterables and array-like objects
33. Object.freeze() and Object.seal() - Prevent object modification
34. JSON Methods - Serialize and parse JSON data
35. Timers - Schedule code execution with timers
36. Math Utilities - Mathematical operations with Math object
37. Property Descriptors - Control object property behavior
38. Array Sorting - Sort arrays correctly with custom comparators
39. String Manipulation - Advanced string manipulation methods
40. Type Conversion - Convert between data types

5. Modern Features (Tips 41-50)

41. Promises - Handle asynchronous operations with Promises
42. Async/Await - Write asynchronous code with async/await
43. Generators - Create iterators with generator functions
44. Generator Delegation - Delegate to other generators with yield*
45. Proxies - Intercept and customize object operations
46. Proxy Validation - Validate object properties with Proxy
47. Reflection API - Manipulate objects with Reflect API
48. WeakMap and WeakSet - Garbage-collected weak references
49. Symbols - Create unique property keys with Symbol
50. Event Loop - Understand JavaScript's event loop and microtasks

6. Performance (Tips 51-60)

51. Memory Management - Manage memory and garbage collection
52. Web Workers - Run JavaScript in background threads
53. Memoization - Cache function results for performance
54. Custom Iterators - Create custom iteration behavior
55. Promise Patterns - Advanced Promise patterns and techniques
56. Function Composition - Compose functions for modularity
57. Currying - Transform multi-argument functions
58. Partial Application - Pre-fill function arguments
59. Function Decorators - Enhance functions with decorators
60. Error Patterns - Advanced error handling patterns

7. Expert (Tips 61-70)

61. BigInt - Work with arbitrarily large integers
62. Private Class Fields - Use # for private class properties
63. Optional Catch Binding - Omit catch parameter when not needed
64. Dynamic Imports - Load modules dynamically
65. Module Features - Advanced ES module features
66. Numeric Separators - Use _ for readable large numbers
67. Promise.any() - Race promises and get first success
68. Logical Assignment - Combine logical operators with assignment
69. WeakRef - Create weak references to objects
70. Top-Level Await - Use await at module top level

8. Masterclass (Tips 71-80)

71. Static Blocks - Initialize static class properties
72. RegExp Match Indices - Get match positions in regex
73. Array Grouping - Group array elements by criteria
74. Object Methods - Modern object manipulation methods
75. String Methods - New string manipulation features
76. Error Cause - Chain errors with cause property
77. SharedArrayBuffer - Share memory between workers
78. Atomics - Perform atomic operations on shared memory
79. Import Assertions - Assert module types during import
80. Class Fields - Declare class fields directly

🚀 How to Use

1. Browse by skill level: Navigate to the folder matching your experience level
2. Read the explanation: Each file starts with a clear explanation of the concept
3. Run the examples: Execute files directly in your terminal or IDE
4. Experiment: Modify examples to deepen your understanding

# Run any tip (example):
node "1. Introduction/tip-01-const-vs-let.js"
node "4. Advanced/tip-30-regex.js"
node "7. Expert/tip-61-bigint.js"

💡 Features

• ✅ Modern JavaScript: ES6+ features and best practices
• ✅ Well-commented: Every example includes detailed explanations
• ✅ Runnable code: All examples can be executed immediately
• ✅ Progressive difficulty: Start simple, advance to expert level
• ✅ Practical examples: Real-world use cases for each concept

📝 Learning Path

Beginners: Start with Introduction → Fundamentals → Intermediate

Intermediate: Focus on Advanced → Modern Features → Performance

Advanced: Dive into Expert → Masterclass

🤝 Contributing

Found an issue or have a suggestion? Feel free to open an issue or submit a pull request!

📄 License

This project is open source. See the LICENSE file for details.

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