January 2018 web platform update

Now widely available on the web platform

Widely available

• Array (initial support): Arrays are ordered lists of JavaScript values. Learn more.

• Array.isArray(): The Array.isArray() static method checks whether a value is an array. Learn more.

• Array iteration methods: Array iteration methods Learn more.

• Array splice(): The array splice() method changes an array in-place. You can use it to delete items, overwrite items, or insert items, starting from an index. Learn more.

• Autofocus: The autofocus HTML attribute gives focus to an element on page load. Learn more.

• background-clip: The background-clip CSS property sets the extent of the background: the padding box, the content box, or the default border box. Learn more.

• calc(): The calc() CSS function computes mathematical expressions such a calc(100%/3 - 1em). Learn more.

• Canvas text metrics: The fillText() and strokeText() methods draw text to a 2D canvas. The measureText() method measures the width and other metrics which can be used to position the text. Learn more.

• HTTP/1.1: HTTP/1.1 is a network protocol used by browsers and servers. It has been superseded by HTTP/2 and HTTP/3. Learn more.

• Map (initial support): Map objects hold key-value pairs and remember the original insertion order of the keys. Learn more.

• :nth-child() (initial support): The :nth-child() and :nth-last-child() CSS functional pseudo-classes match elements by the relative position of elements (first, second, third, fourth, and so on), counted from the first or last sibling. Learn more.

• Promise (initial support): A promise represents an asynchronous operation which eventually succeeds or fails. Learn more.

• requestAnimationFrame(): The requestAnimationFrame() method schedules a function that runs before the next repaint. You can use it to animate content with JavaScript. Learn more.

• <input type="search">: The <input> HTML element with the type="search" attribute represents a text field for search queries, which might be styled differently by the browser. Learn more.

• Set (initial support): Set objects store unique values of any type. Learn more.

• text-indent: The text-indent CSS property sets the size of the empty space (indentation) at the beginning of lines in a text. Learn more.

• Typed arrays (initial support): Typed arrays are ordered lists of JavaScript values, where all values are of the same numerical type, such as 8-bit integers or 32-bit floating point numbers. Learn more.

• WebVTT: WebVTT is a captions and subtitles format. WebVTT files are loaded using the <track> element, and the VTTCue API can be used to create or update cues dynamically. Learn more.

• XMLHttpRequest: The XMLHttpRequest API makes HTTP requests. It's the predecessor to fetch(). Also known as XHR. Learn more.

Now available in Firefox

Limited availability

• Promise finally(): The promise finally() method executes a function when the promise settles (resolves or rejects). Learn more.

Now available in Firefox for Android

Limited availability

• Promise finally(): The promise finally() method executes a function when the promise settles (resolves or rejects). Learn more.