What’s New in ES2024?

ECMAScript 2024 (ES15) introduces several significant features aimed at enhancing JavaScript’s functionality and developer experience.

Here are some of the key updates:

Pipe Operator (|>)

This operator enables more readable and maintainable code by allowing the output of one function to be used as the input for the next, streamlining data transformations.

For example:

const result = value |> firstFunction |> secondFunction;

This eliminates the need for deeply nested function calls, improving code clarity.

Records and Tuples

These immutable data structures ensure that their contents cannot be changed after creation, providing a robust way to manage immutable data in JavaScript.

Records are like objects, and tuples are like arrays but immutable. For instance:

const record = #{ name: "Alice", age: 30 };
const tuple = #["apple", "banana"];

This helps in maintaining predictable state management in applications

Array Grouping Methods

The Array.prototype.groupBy and Array.prototype.groupByToMap methods allow you to group array elements based on a callback function, simplifying data categorization.

For example:

const animals = [
  { name: "Lion", type: "Mammal" },
  { name: "Shark", type: "Fish" },
];
const grouped = animals.groupBy((animal) => animal.type);

This results in a more organized and manageable data structure.

Temporal API

This new API provides a modern approach to handling dates and times, addressing many shortcomings of the existing Date object.

It allows for more precise and flexible date-time operations, such as:

const now = Temporal.Now.plainDateTimeISO();
const birthday = Temporal.PlainDate.from("2000-01-01");
const age = now.since(birthday);

This is especially useful for internationalization and dealing with different time zones.

Top-Level Await

This feature allows the use of await at the top level of modules, simplifying asynchronous code by removing the need to wrap await calls in async functions.

For example:

const response = await fetch("https://api.example.com/data");
const data = await response.json();
console.log(data);

This enhances code readability and reduces boilerplate code.

RegExp Match Indices

The d flag in regular expressions provides start and end positions of matched substrings, offering more detailed match information.

For example:

const regex = /(foo)/d;
const match = regex.exec("foo bar foo");
console.log(match.indices);

This is useful for more precise substring manipulation.

Enhanced Error Cause

This feature allows errors to include a cause property, improving error handling and debugging by linking related errors together.

For instance, we set the original cause to the error:

try {
 // some code
} catch (originalError) {
 throw new Error("Enhanced error", { cause: originalError });
}

This makes it easier to trace the root cause of errors in complex applications

These features collectively enhance JavaScript’s robustness, readability, and functionality, making it a more powerful and developer-friendly language.