ECMAScript 2017 - ES8

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Given the constraints and the detailed nature of your request, I'll provide a concise summary of ECMAScript 2017 (ES8) features, along with examples, comparisons, and relevant links. This overview will focus on the key features rather than an exhaustive paragraph-per-feature breakdown.

ECMAScript 2017, also known as ES8, introduced several significant features and improvements to JavaScript, enhancing its capabilities for developers and making the language more powerful and flexible.

• Language Documentation: s://www.ecma-international.org/publications-and-standards/standards/ecma-262/
• GitHub Repository: s://github.com/tc39/ecma262
• Official Website: s://www.ecma-international.org/
• Wikipedia: s://en.wikipedia.org/wiki/ECMAScript#8th_Edition_-_ECMAScript_2017

Async Functions provide a simpler and cleaner way to work with asynchronous code, using the `async` and `await` keywords. JavaScript Code Example: ```javascript async function fetchData() {

 const data = await fetch('url');
 return data.json();

} ``` In comparison, Python uses async def and await for similar functionality. Java has CompletableFuture for asynchronous programming, and TypeScript, being a superset of JavaScript, directly supports `async` and `await`.

These functions return an array of the object's enumerable property values and an array of the object's own enumerable string-keyed property `[key, value]` pairs, respectively. JavaScript Code Example: ```javascript const obj = { a: 1, b: '2', c: true }; console.log(Object.values(obj)); // [1, “2”, true] console.log(Object.entries(obj)); // "a", 1], ["b", "2"], ["c", true ``` Python's `dict.values()` and `dict.items()` offer similar functionality. Java can use `Map.values()` and `Map.entrySet()`. TypeScript supports these JavaScript methods directly.

`String.prototype.padStart()` and `String.prototype.padEnd()` allow padding to the start and end of a string, respectively. JavaScript Code Example: ```javascript console.log('ES8'.padStart(4, '0')); // “0ES8” console.log('ES8'.padEnd(4, '0')); // “ES80” ``` This functionality is akin to Python's `str.ljust()`, `str.rjust()`, and `str.center()` methods. Java's `String.format()` can achieve similar outcomes. TypeScript inherits these methods from JavaScript.

This method returns all own property descriptors of a given object. JavaScript Code Example: ```javascript const obj = { a: 1 }; console.log(Object.getOwnPropertyDescriptors(obj)); ``` This feature is unique to JavaScript and doesn't have a direct equivalent in Python or Java, where property descriptors are not a commonly used pattern. TypeScript, as with other ES8 features, supports this method.

Trailing commas are now allowed in function parameter lists and calls, improving version control diffs. JavaScript Code Example: ```javascript function example(a, b, c,) {

 // Function body

} example(1, 2, 3,); ``` This syntax improvement is more about consistency with array and object literals than a new feature in other languages. Python supports trailing commas in function definitions and calls. Java does not support trailing commas in method or constructor parameter lists.

`SharedArrayBuffer` and `Atomics` provide primitives for high-performance, concurrent programming, allowing data to be shared between workers/threads. JavaScript Code Example: ```javascript // Not provided due to complexity and the need for a multi-threaded context ``` This feature introduces concurrency features reminiscent of those found in languages like Java, which has a rich set of concurrency utilities. Python has the `threading` and `multiprocessing` modules, but JavaScript's shared memory model is unique due to its web-based, single-threaded context. TypeScript supports these features as they are part of the ECMAScript standard.

ECMAScript 2017 brought significant enhancements to JavaScript, including syntactic sugar for easier readability and new functionalities for more efficient programming. Each feature has parallels in other programming languages, indicating JavaScript's ongoing evolution to match and sometimes exceed the capabilities of its contemporaries. For detailed exploration of all features and updates, the provided links to official resources are invaluable.

https://en.wikipedia.org/wiki/ECMAScript_version_history#ES2017

Snippet from Wikipedia: ECMAScript version history

ECMAScript is a JavaScript standard developed by Ecma International. Since 2015, major versions have been published every June.

ECMAScript 2024, the 15th and current version, was released in June 2024.

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