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Software Development Terms Beginning with D


Data is the content of a document. In order words, the text and graphics on a page are the document's data.

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Data Types in JavaScript

JavaScript data types refer to the kind of values you can assign to JavaScript variables.

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Database API

Database APIs connect a caller to the resources and services of a database management system.

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Declaration means to declare the creation of variables and functions.

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Declaration Statement in JavaScript

A declaration statement is a piece of code that declares the creation of variables and functions.

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To decode means converting code from its coded form into its standard form.

Decode (Computing)

To decode means converting bits (computer-readable characters) into human-readable characters.

For instance, 9829 is the decimal form of the binary number 10011001100101.

In other words, using 9829 to represent 10011001100101 means you've decoded 10011001100101 into its human-readable form.

Knowing how to decode is beneficial. And having some decoding converters can come in handy.

Deep Copy

You do deep copy when you clone items without creating references.

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Deep Object in JavaScript

A deep object is one that contains a non-primitive item.

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Default Export (ES Modules)

Default export is a technique developers use to export code anonymously (namelessly).

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Default Function Properties in JavaScript

Default function properties are the built-in variables available in every function declaration.

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Default Parameter in JavaScript

Default parameters allow you to initialize your function's parameters with default values.

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dependency is a file your script requires to work as intended. So, in import { variable } from "./path/to/module.js"module.js is the dependency file because it is a script our app depends on to function as designed.


Deserialization reconstructs serialized data from a format transmittable between clients and servers to a native object.

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Destructuring Assignment in JavaScript

The destructuring assignment is a unique technique you can use to copy the values of an object or array into new variables.

Detached HEAD State (Git)

A detached HEAD state means Git detached (removed) the HEAD pointer from the branch it was previously on and moved it to the commit history (or fetched repository) you switched to.

In other words, a "detached HEAD state" implies that the HEAD pointer is not pointing to any branch. Instead, it points to a commit (or fetched repo).

Note the following:

  • Any changes you commit in the detached state will not get tracked by any branch. As such, you will have no way to reference the commits.
  • The detached state is best for reviewing old commits or fetched content—not for working.
  • Suppose you wish to retain the changes you made in the detached state. In that case, create a new branch from the commit with the git switch -c new-branch-name command.


A digit is each individual character of a numeral.

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Directory (Computing)

A directory is another name for a folder.

Distributed (Git)

In Git, "distributed" means a project's entire content gets distributed whenever you share its .git repository.

In other words, whoever a project's .git repository gets distributed to will get all the files, commits, and branches in that repository.


Git's "distributed" system is in sharp contrast to other version control systems.

Git distributes by sharing everything inside the repository it is tracking.

However, virtually all other VCSs only share the specific file version a user has explicitly checked out from the central/local database.

Distribution Code

A distribution code is the minified and optimized version of the source code.

In other words, a distribution code (the build step's output) refers to the JavaScript file a bundler generates automatically for your project.

DNS Hierarchy

DNS Hierarchy is a system used to sort the parts of a domain name according to their importance.

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do…while Loop Statement in JavaScript

A do...while loop instructs the computer to do the task in the code block once. Then, while the specified condition is true, it should repeat the block's execution.

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A <!DOCTYPE> declaration informs browsers about a document's type and version.

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A document is a page used to contain text, or graphics, or both.

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DOM Storage

DOM storage is the JavaScript API browsers provide for storing data locally and securely within a user's browser.

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Domain Name

A domain name is a website's name.

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Domain Name Server

A Domain Name Server (DNS) is the server (or computer) used to store domain names and their corresponding IP addresses.

  • Domain name servers are sometimes called nameservers or DNS servers.
  • IP addresses typically have two nameservers.
  • You can use ICANN's lookup tool to get a website's nameservers and other domain information.

Domain Name System

A Domain Name System (DNS) is the system (technique) by which domain names get converted to their equivalent IP (Internet Protocol) addresses.

Dot (RegExp)

Regular expression's dot operator (.) specifies that you wish to find any character that is not the newline or any other line terminator characters.

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Dot All (RegExp)

Regular expression's dot all flag (s) tells the computer to allow a wildcard operator (.) to match all characters—including a newline character.

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Dummy (TDD)

dummy is a test double used to mimic the value of a specific dependency.

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