Web-Related Terms Beginning with T
Temporal Dead Zone (JS)​
A temporal dead zone (TDZ) is the area of a block where a variable is inaccessible until the moment the computer completely initializes it with a value.
Terminal​
A terminal is a computer's text interface allowing you to type commands for the computer to run.
Ternary Operator (JS)​
Ternary operators are operators that accept three operands. An example is the conditional operator.
Test Doubles (TDD)​
Test doubles are the imitation objects used to mimic real dependencies like databases, libraries, networks, and APIs.
Test Runner​
A test runner is a tool developers use to run a test script and print the test's results on the command line (CLI).
Test-Driven Development​
Test-driven development is a coding practice where you write the result you want your program to produce before creating the program.
test()
in JavaScript​
test() tests its string argument for an occurrence of a regular expression.
Text​
Text is the characters of a piece of writing.
Text Markup​
Text Markup means Text Note (that is, the note added to a text to help typesetters (or computers) better understand how to present the marked-up text).
Textual Data​
Textual data are the written contents of a page, such as letters (e.g., A, B, C), numbers (e.g., 1, 2, 3), symbols (e.g., $, #, +), and code (e.g., <input>
, body { background: #A18A77; }
, if (condition) { //execute code }
).
Thenable (JavaScript)​
Thenable in JavaScript refers to any object that contains a then()
 method.
this
(JS)​
JavaScript's this keyword refers to the owner object of the keyword's method or the this
value of an arrow function's lexical context.
TO (RegExp)​
A regular expression's TO operator ([a-z]
) defines the range of characters you wish to find in a single character's position.
toLowerCase()
in JavaScript​
toLowerCase() returns the lowercase version of its calling string.
Top-Level Domain​
The top-level domain (TLD) is what follows the domain name in a URL.
Top-Level Module (JavaScript)​
A top-level module is a script containing other modules.
toString()
JavaScript Number Method​
toString() converts a number to a string of a specified radix.
toUpperCase()
in JavaScript​
toUpperCase() returns the uppercase version of its calling string.
trim()
in JavaScript​
trim() trims whitespace from both ends of a string.
trimEnd()
in JavaScript​
trimEnd() trims whitespace only at the end of a string.
trimStart()
in JavaScript​
trimStart() trims whitespace only at the beginning of a string.
Truthy (JS)​
Truthy values are values JavaScript considers to be true.
All JavaScript's values are true except 0
(zero), false
, ""
(empty string), NaN
, null
, undefined
, and 0n
(BigInt zero)—which are falsy.