ECMAScript 2023
New Features in JavaScript 2023
ECMAScript 2023 is supported in all modern browsers since July 2023:
| Chrome 110 |
Edge 110 |
Firefox 115 |
Safari 16.4 |
Opera 96 |
| Feb 2023 | Feb 2023 | Jul 2023 | Mar 2023 | May 2023 |
JavaScript Array findLast() Method
ES2023 added the findLast() method that will start from the end of an array and return the value of the first element that satisfies a condition.
Example
const temp = [27, 28, 30, 40, 42, 35, 30];
let high = temp.findLast(x => x > 40);
Try it Yourself »
JavaScript Array findLastIndex() Method
The findLastIndex() method finds the index of the last element that satisfies a condition.
Example
const temp = [27, 28, 30, 40, 42, 35, 30];
let pos = temp.findLastIndex(x => x > 40);
Try it Yourself »
JavaScript Array toReversed() Method
ES2023 added the Array toReversed() method as a safe way to reverse an array without altering the original array.
The difference between the new toReversed() method and the old reverse() method is that the new method creates a new array, keeping the original array unchanged, while the old method altered the original array.
Example
const months = ["Jan", "Feb", "Mar", "Apr"];
const reversed = months.toReversed();
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JavaScript Array toSorted() Method
ES2023 added the Array toSorted() method as a safe way to sort an array without altering the original array.
The difference between the new toSorted() method and the old sort() method is that the new method creates a new array, keeping the original array unchanged, while the old method altered the original array.
Example
const months = ["Jan", "Feb", "Mar", "Apr"];
const sorted = months.toSorted();
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JavaScript Array toSpliced() Method
ES2023 added the Array toSpliced() method as a safe way to splice an array without altering the original array.
The difference between the new toSpliced() method and the old splice() method is that the new method creates a new array, keeping the original array unchanged, while the old method altered the original array.
Example
const months = ["Jan", "Feb", "Mar", "Apr"];
const spliced = months.toSpliced(0, 1);
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JavaScript Array with() Method
ES2023 added the Array with() method as a safe way to update elements in an array without altering the original array.
Example
const months = ["Januar", "Februar", "Mar", "April"];
const new = months.with(2, "March");
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#! JavaScript Shebang
In operating systems, a shebang (also known as hashbang, pound-bang, sharp-exclamation or hash-pling) is a sequence of two characters: a number sign (#) and an exclamation mark (!).
#! at the beginning of a script tells the operating system what interpreter should be used to execute the script:
Example
#!/usr/bin/env node
The example above tells the operating system to use the node program to run the script.
Now, you can run JavaScript code with ./fileName.js instead
of node fileName.js.
