2015
30 featuresThe @supports at-rule applies styles based on a browser's support for CSS features, such as a CSS property and value. Also known as feature queries.
The animation CSS property animates an element's style over time, using keyframes described in @keyframes rules.
The CSS object model API reads, creates, and modifies CSS stylesheets and inline styles. Also known as CSSOM.
Flexbox is a one-dimensional layout system, which places content either horizontally or vertically, with optional wrapping.
The HTTP/2 protocol is a major revision of the HTTP network protocol, providing improved performance and efficiency by using a single TCP connection to send multiple streams of data at once.
The codePointAt() method returns the numeric value of the UTF-16 code point at an index of the string. The fromCodePoint() method returns a string created from one or more code points.
The includes() method of strings returns whether a search string appears within the string.
The String.raw() static method interpolates template literal substitutions, but ignores escape sequences. It is the tag function for template literals.
The repeat() method of strings returns the original string repeated a number of times.
The startsWith() and endsWith() methods of strings returns whether a search string appears at the beginning or end of the provided string.
A Symbol value is a unique, non-enumerable primitive value used for encapsulation or information hiding. For example, a symbol can be a key of an object that can never collide with any other key.
The transition shorthand CSS property sets how changes to an element's styles may occur over time. Transitions can be applied to specific CSS properties, all properties, or none.
Unicode point escapes (\\u{}) represent Unicode characters within strings.
A WeakSet object stores unique values of any type without creating strong references to the values, such that membership in the set does not prevent garbage collection of the value.
The word-break CSS property sets how lines break within words.
Channel messaging communicates one-to-one between browsing contexts on the same origin, such as between <iframe> elements or two documents using a shared worker.
The performance global object and the PerformanceObserver API provide access to performance-related information for the current execution context.
The CanvasRenderingContext2D API is the "2d" rendering context for the <canvas> element. It represents a flat, two-dimensional space for drawing graphics and animations.
The ::before and ::after CSS pseudo-elements select inline boxes preceding and following an element. They are often used with the content property to generate cosmetic content.
The ::first-letter CSS pseudo-element selects the first letter in an element for styling.
The ::first-line CSS pseudo-element selects the first line of text in an element for styling.
The :empty CSS pseudo-class matches elements without child elements.
The :lang() CSS functional pseudo-class matches elements based on their content language.
The :nth-child() and :nth-last-child() CSS functional pseudo-classes match elements based on their index within a list of elements. The :first-child and :last-child pseudo-classes match the first and last element in a list, and the :only-child pseudo-class matches an element with no siblings.
The :nth-of-type() and :nth-last-of-type() CSS functional pseudo-classes match elements based on their position among siblings of the same type. The :first-of-type, :last-of-type, and :only-of-type pseudo-classes match the first, last, and only elements of its type.
The :root pseudo-class matches the root element of the document, usually the <html> element.
The :target CSS pseudo-class matches the element with an ID matching the URL fragment.
The <a> element creates a hyperlink to any resource that's accessible via a URL, such as web pages, files, email addresses, or locations within the same page.
The <abbr> HTML element represents an abbreviation or acronym.
The <address> element represents contact information for a person or people, or for an organization.