29 docs tagged with "Variable"

Array destructuring is a unique technique that allows you to neatly extract an array's value into new variables.

An array object is an element used to bundle multiple unnamed values into a single item. A pair of square brackets defines JavaScript's array object.

An array bundles values that a user cannot name, while an object bundles values that a user can name.

An asynchronous function is a function that runs in its own timing—without waiting for another function to finish its execution first.

JavaScript data types refer to the kind of values you can assign to JavaScript variables. The two main ones are primitives and non-primitive.

Declaration declares the creation of variables and functions. Initialization occurs when you assign an initial value to a variable.

Hoisting refers to JavaScript giving higher precedence to the declaration of variables, classes, and functions during a program's execution.

A JavaScript function is an executable piece of code used to bundle a block of zero or more statements.

Lexical scope is the definition area of an expression. Therefore, an item's lexical scope is the place in which the item got created.

JavaScript's match() method creates a new array containing all the patterns that match the method's regular expression argument.

matchAll() creates a new iterator object containing all the patterns—including capturing groups—that match the method's regular expression argument.

A namespace is a named container used to store objects of any type. It allows you to use the same object multiple times in the same script.

A non-primitive data is a JavaScript value that can contain multiple other values. Object is the only non-primitive data that exist in JavaScript.

Object destructuring is a unique technique that allows you to neatly extract an object's value into new variables.

An object is an element you can use to bundle up multiple named values into a single item. A pair of braces define JavaScript's properties object.

JavaScript's pop() method removes and returns its calling array's last item. It does not accept any argument.

A JavaScript primitive data type is any plain value used to program a webpage. Examples are Number, Boolean, String, Null, and BigInt.

JavaScript's push() method adds its arguments to the end of its calling array and returns the calling array's new length.

A regular expression (RegExp) is a JavaScript element used to bundle the patterns you wish to find in a specific string of characters.

The rest operator is a syntax used to encase the rest of specific user-supplied values into a JavaScript array. It works with functions.

JavaScript scope is all about space. It refers to the area where an item (such as a variable) is visible and accessible to other code.

JavaScript's shift() method removes and returns its calling array's first item. It does not accept any argument.

JavaScript's slice() method duplicates a specified part of its calling array into a new array—without altering the original array.

JavaScript's slice() method duplicates a specified part of its calling string into a new string—without altering the original string.

JavaScript's splice() method alters its calling array by adding or removing a specific number of items to/from it.

A JavaScript statement is a piece of code used to instruct the computer on an action to execute. There are five typical types of statements.

A temporal dead zone is the area of a block where a variable is inaccessible until the computer completely initializes it with a value.

JavaScript's unshift() method adds its arguments to the beginning of its calling array and returns the calling array's new length.

A JavaScript variable is a container used to store data. JavaScript variables differ from mathematical or other generic variables.