ECMA International has approved ECMAScript 2026, the 17th edition of the specification for the JavaScript programming language. The standards organization approved the specification on June 30.
ECMAScript 2026 adds methods for math, iterators, arrays, maps, encoding, and JSON. The additions include Math.sumPrecise for summing an iterable of numbers of varying magnitude while minimizing precision loss; Iterator.concat for sequencing iterators; Array.fromAsync for constructing arrays from async iterables and other async sources; Error.isError for identifying error objects; methods to Map.prototype and WeakMap.prototype for providing a default value to use during retrieval when a key is not already present; methods to Uint8Array for converting to and from strings of hexadecimal-based and base64-encoded binary data; a parameter to JSON.parse revivers to access the matched segment of JSON source; and JSON.rawJSON for fine control over JSON.stringify output for primitive values.