JSON→URL is a language-independent data interchange format for the

JSON JSON (JavaScript Object Notation, pronounced ; also ) is an open standard file format and data interchange format that uses human-readable text to store and transmit data objects consisting of attribute–value pairs and arrays (or other ser ...

data model suitable for use within a

URL A Uniform Resource Locator (URL), colloquially termed as a web address, is a reference to a web resource that specifies its location on a computer network and a mechanism for retrieving it. A URL is a specific type of Uniform Resource Identifie ...

URI Uri may refer to: Places * Canton of Uri, a canton in Switzerland * Úri, a village and commune in Hungary * Uri, Iran, a village in East Azerbaijan Province * Uri, Jammu and Kashmir, a town in India * Uri (island), an island off Malakula Islan ...

query string. It is defined by an

open specification An open standard is a standard that is openly accessible and usable by anyone. It is also a prerequisite to use open license, non-discrimination and extensibility. Typically, anybody can participate in the development. There is no single definition ...

, though not through a standards body.

Data types and syntax

JSON→URL implements the JSON data model:, with support for the following data types * Number: a signed decimal number that may contain a fractional part and may use exponential

E notation Scientific notation is a way of expressing numbers that are too large or too small (usually would result in a long string of digits) to be conveniently written in decimal form. It may be referred to as scientific form or standard index form, o ...

, but cannot include non-numbers such as NaN. The format makes no distinction between integer and floating-point. *

Boolean Any kind of logic, function, expression, or theory based on the work of George Boole is considered Boolean. Related to this, "Boolean" may refer to: * Boolean data type, a form of data with only two possible values (usually "true" and "false" ...

: either of the values true or false * null: an empty value, using the word null *

String String or strings may refer to: *String (structure), a long flexible structure made from threads twisted together, which is used to tie, bind, or hang other objects Arts, entertainment, and media Films * ''Strings'' (1991 film), a Canadian anim ...

: a sequence of zero or more

Unicode Unicode, formally The Unicode Standard,The formal version reference is is an information technology Technical standard, standard for the consistent character encoding, encoding, representation, and handling of Character (computing), text expre ...

characters. Strings may be delimited with single-quotation marks if the unquoted value would otherwise be interpreted as a boolean, null, or number. Otherwise, they need not be quoted. Characters which are not valid in a URL must be percent encoded.

Space Space is the boundless three-dimensional extent in which objects and events have relative position and direction. In classical physics, physical space is often conceived in three linear dimensions, although modern physicists usually consider ...

is encoded as + or %20. * Array: an ordered list of one or more values, each of which may be of any type. Arrays use parentheses notation with

comma The comma is a punctuation mark that appears in several variants in different languages. It has the same shape as an apostrophe or single closing quotation mark () in many typefaces, but it differs from them in being placed on the baseline ...

-separated elements. *

Object Object may refer to: General meanings * Object (philosophy), a thing, being, or concept ** Object (abstract), an object which does not exist at any particular time or place ** Physical object, an identifiable collection of matter * Goal, an ai ...

: a collection of one or more name–value pairs where the names (also called keys) are strings. Objects are intended to represent associative arrays, where each key is unique within an object. Objects are delimited with parentheses and use

s to separate each pair, while within each pair the colon character separates the key or name from its value. *

Empty Empty may refer to: ‍ Music Albums * ''Empty'' (God Lives Underwater album) or the title song, 1995 * ''Empty'' (Nils Frahm album), 2020 * ''Empty'' (Tait album) or the title song, 2001 Songs * "Empty" (The Click Five song), 2007 * ...

: the empty composite value

Differences from JSON

JSON→URL implements the

data model, however, it does not differentiate between an empty object and an empty array. Instead, it defines an empty composite value as ().

Data portability

JSON→URL exchange in an open ecosystem must be encoded in

UTF-8 UTF-8 is a variable-width encoding, variable-length character encoding used for electronic communication. Defined by the Unicode Standard, the name is derived from ''Unicode'' (or ''Universal Coded Character Set'') ''Transformation Format 8-bit'' ...

. The encoding supports the full Unicode character set, including those characters outside the

Basic Multilingual Plane In the Unicode standard, a plane is a continuous group of 65,536 (216) code points. There are 17 planes, identified by the numbers 0 to 16, which corresponds with the possible values 00–1016 of the first two positions in six position hexadecimal ...

(U+10000 to U+10FFFF). Unlike

, JSON→URL does not define a separate syntax for escaping characters within a string literal. Such characters are simply composed of one or more percent encoded

octets Octet may refer to: Music * Octet (music), ensemble consisting of eight instruments or voices, or composition written for such an ensemble ** String octet, a piece of music written for eight string instruments *** Octet (Mendelssohn), 1825 compos ...

. Numbers in JSON→URL are agnostic with regard to their representation within programming languages. While this allows for numbers of arbitrary precision to be serialized, it may lead to portability issues. For example, since no differentiation is made between integer and floating-point values, some implementations may treat 42, 42.0, and 4.2E+1 as the same number, while others may not. The JSON→URL standard makes no requirements regarding implementation details such as overflow,

underflow The term arithmetic underflow (also floating point underflow, or just underflow) is a condition in a computer program where the result of a calculation is a number of more precise absolute value than the computer can actually represent in memory o ...

, loss of precision, rounding, or

signed zeros Signed zero is zero with an associated sign. In ordinary arithmetic, the number 0 does not have a sign, so that −0, +0 and 0 are identical. However, in computing, some number representations allow for the existence of two zeros, often denoted by ...

Semantics

While JSON→URL provides a syntactic framework for data interchange, unambiguous data interchange also requires agreement between producer and consumer on the semantics of a specific use of the JSON→URL syntax. One example of where such an agreement is necessary is the serialization of data types local to a specific implementation (e.g.

Java Java (; id, Jawa, ; jv, ꦗꦮ; su, ) is one of the Greater Sunda Islands in Indonesia. It is bordered by the Indian Ocean to the south and the Java Sea to the north. With a population of 151.6 million people, Java is the world's List ...

JavaScript JavaScript (), often abbreviated as JS, is a programming language that is one of the core technologies of the World Wide Web, alongside HTML and CSS. As of 2022, 98% of Website, websites use JavaScript on the Client (computing), client side ...

) that are not defined in the JSON→URL specification, such as Date.

References

External links

* {{Authority control Computer-related introductions in 2019 JSON Data serialization formats Open formats