Top 10 ES6 Features that Every Developer Should know

**1. let and const:
**Block-scoped variable declarations. 'let' allows reassignment, 'const' doesn't. Prevents hoisting issues and unintended global variables. Improves code predictability and encourages better practices for variable scope and mutability.

**2. Arrow Functions:
**Concise syntax for function expressions. Lexically binds 'this', solving context issues in callbacks. Can't be used as constructors or methods needing their own 'this' binding. Simplifies code and reduces 'this'-related errors.

**3. Template Literals:
**Uses backticks for strings. Allows multi-line strings and interpolation with ${expression}. Improves readability when constructing complex strings or HTML templates. Supports tagged templates for custom string processing.

**4. Destructuring Assignment:
**Extracts values from arrays or object properties into distinct variables concisely. Useful for handling function returns, import statements, and complex data structures. Enhances code readability and reduces lines of code.

**5. Enhanced Object Literals:
**Shorthand syntax for defining object methods and properties. Allows computed property names. Simplifies object creation, especially when property names match variable names. Makes object definitions more concise and readable.

**6. Default Parameters:
**Allows setting default values for function parameters. Reduces need for manual parameter checks. Improves function flexibility and readability. Default values are used when arguments are undefined.

**7. Rest and Spread Operators:
**Rest (...) collects multiple elements into an array. Spread (...) expands arrays or objects. Useful in function arguments, array manipulation, and object composition. Simplifies working with arrays and function parameters.

**8. Promises:
**Represents asynchronous operations. Provides cleaner alternative to callbacks. Has states: pending, fulfilled, or rejected. Includes methods like then() and catch() for handling outcomes. Improves asynchronous code structure and error handling.

**9. Classes:
**Syntactical sugar over prototype-based inheritance. Provides familiar syntax for object-oriented programming. Includes constructors, methods, and inheritance. Doesn't change JavaScript's prototype-based nature but improves code organization and readability.

**10. Modules:
**Allows code organization into separate files. Uses import and export statements. Supports default and named exports. Improves code maintainability, reusability, and helps manage dependencies. Replaces older module patterns like CommonJS.