What are the new features of es6?

ES6 new features include: 1. Block-level scope and constant declaration; 2. Arrow functions; 3. Default parameter values; 4. Extension operator; 5. Destructuring assignment; 6. Classes and modules; 7 , Simplified object literals; 8. Iterators and generators; 9. Promise objects; 10. Template literals.

# Operating system for this tutorial: Windows 10 system, Dell G3 computer.

ECMAScript 6 (ES6 for short), also known as ECMAScript 2015, is an important update to the JavaScript programming language that introduces many new features and syntax improvements to provide more powerful and modern development capabilities. Here are some of the major new features of ES6:

1. Block-level scope and constant declarations (let and const): ES6 introduces block-level scope variable declarations, through let# The ## and const keywords can declare variables and constants in block-level scope and will not be affected by variable promotion.

2. Arrow function: Arrow function is a more concise function definition syntax, you can use

   => instead of the traditional function keyword , while having a more concise syntax and the function of binding this.

3. Default parameter values: ES6 allows setting default values ​​for parameters in function definitions, simplifying parameter passing when calling functions. If the corresponding parameters are not provided when calling, the default values ​​will be used.

4. Spread Operator (Spread Operator): The spread operator allows an array or object to be expanded into independent elements, simplifying operations such as array merging, copying, and object property expansion.

5. Destructuring Assignment: Destructuring assignment allows values ​​to be extracted from arrays or objects and assigned to variables, allowing the value of the variable to be quickly obtained and exchanged.

6. Classes and Modules: ES6 introduces the concept of classes. Classes can be defined through the class keyword and inherited using extends . At the same time, ES6 also introduces modular syntax, and modules can be imported and exported through the export and import keywords.

7. Simplified object literals (Enhanced Object Literals): ES6 allows the use of variables as property names in object literals, and also provides support for abbreviated syntax and calculated property names.

8. Iterators and Generators (Iterators and Generators): ES6 introduces the concepts of iterators and generators, which can be used to traverse collections through custom iterators, and generator functions Can simplify the processing of asynchronous operations.

9. Promise object: Promise is a new way of handling asynchronous operations, which can better handle asynchronous code flow and avoid the problem of callback hell.

10. Template Literals: Template literals allow syntax similar to variable interpolation and multi-line strings to be used in strings by wrapping the string with backticks (`).

These are just some of the major new features of ES6, which make JavaScript development more convenient and efficient, and provide more modern syntax and functions.

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