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Software Development Terms Beginning with R


Radix indicates the number of unique digits from zero (0) that you can use to express numbers in a standard positional numeral system.

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React Component

A component is a JavaScript function (or class) that can accept arbitrary inputs (called "props") and returns an element (UI).

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React Component Testing Tool

A React component testing tool provides helpful APIs for defining a component's test cases.

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React Element

React element is the specific user interface (UI) you want to see displayed on-screen.

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React Hooks

React hooks are functions used in a function component to hook into React's state object, lifecycle methods, and other React features without writing a class component.

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React Props

React props are parameters used to pass arguments to components.

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React Router

React Router is a popular routing library that tells React the specific component it should render based on the route (file path) a user requested through the URL.

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React State

React state is a built-in object used to store a component's values that are likely to change over time.

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React is a component-based JavaScript library used to build user interfaces (UI) efficiently.

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Recursion is a method by which a problem gets solved through iteration.

In other words, a recursive function is a function that repeatedly invokes itself infinitely (or until something stops it).

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Regular Expression

A regular expression (RegExp) is a JavaScript element used to bundle the patterns you wish to find in a specific string of characters such as text, password, and email address.

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Relative Length Units

Relative length units are dynamic units. In other words, the sizes of things expressed in any of the relative length units will always be dependent on another length.

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Remote API

Remote APIs connect a caller to the resources and services of a remote system.

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Remote Repository

A remote repository is the duplicated copy of a project's .git repository hosted elsewhere—on the internet, on a network somewhere else, or in a different location on your computer.

Repeat (RegExp)

Regular expression's repeat operator ({...}) specifies that you wish to find a repeated occurrence of the operator's preceding item.

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A repertoire (also called character set) is a group of characters collated for a specific purpose.

The purpose for collating characters could be computer related, like coding, or non-computer related, like music.

Here are some examples:

  • ♠ ♠ ♥ ♥ ♣ ♣ ♦ ◊ is the symbols character set of a playing card suit. It consists of eight individual characters.
  • 9817 is the repertoire of a numeral value. It consists of four unique characters.

replace() in JavaScript

replace() returns a new version of its calling string after replacing some specified patterns with a given replacement.

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A repository is another name for a folder.

Rest Operator in JavaScript

The rest operator is used to put the rest of some specific user-supplied values into a JavaScript array.

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Responsive Web Design (RWD)

Responsive web design (RWD) means designing web pages to display nicely on the screen sizes you intend to support (mobiles, tablets, and desktops).

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Rest Parameter in JavaScript

A JavaScript rest parameter consists of the rest operator and a regular parameter.

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Rest Variable in JavaScript

A JavaScript rest variable consists of the rest operator and a regular variable.

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Restartable Iterator

A restartable iterator is an object you can use numerous times. An example is the JavaScript array.

Root Directory

Root directory refers to the folder containing all other files and sub-folders of a specific project.

In other words, a root repository is a working directory that houses everything concerning a particular project.

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return Keyword in JavaScript

The return keyword ends its function's execution and returns the specified expression (or undefined if you provide no expression).

Root-Level Domain

The root-level domain ("") is the highest hierarchy level of any domain name system.

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Router (Internet)

A router is a piece of electronic device that routes (directs) the internet to all your devices.

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Router (Programming)

A router is a code logic used to handle a client's request to a specific file path.

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Runtime (also called execution time) is the time during which a program is running.

In other words, runtime is the execution period (or lifecycle phase) of a program—which begins from the time the program is invoked and ends when the program's invocation is closed.