In ECMAScript 2025, JavaScript gets a class Iterator with iterator helper methods. This class conflicts with TypeScript’s existing types for iterators. In this blog post, we explore why that is and how TypeScript solves that conflict.

2ality – JavaScript and more

22.06.2025

TypeScript: checking Map keys and Array indices

JavaScript has two common patterns: Maps: We check the existence of a key via .has() before retrieving the associated value via .get(). Arrays: We check the length of an Array before performing an indexed access. These patterns don’t work as well in TypeScript. This blog post explains why and presents alternatives.

2ality – JavaScript and more

24.06.2025

Tips for making regular expressions easier to use in JavaScript

In this blog post, we explore ways in which we can make regular expressions easier to use.

2ality – JavaScript and more

27.06.2025

Ecma International approves ECMAScript 2025: What’s new?

On 25 June 2025, the 129th Ecma General Assembly approved the ECMAScript 2025 language specification (press release), which means that it’s officially a standard now. This blog post explains what’s new.

home›2ality – JavaScript and more

2ality – JavaScript and more

Software

How TypeScript solved its global `Iterator` name clash

TypeScript: checking Map keys and Array indices

Tips for making regular expressions easier to use in JavaScript

Ecma International approves ECMAScript 2025: What’s new?

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2ality – JavaScript and more