Scope is the region of the codebase over which an identifier is valid. A lexical environment is a mapping between identifier names and the values associated with them. Scope is formed of a linked nesting of lexical environments, with each level in the nesting corresponding to a lexical environm...
What is variable hoisting in JavaScript? JavaScript Hoisting refers tothe process whereby the interpreter allocates memory for variable and function declarations prior to execution of the code. Declarations that are made using var are initialized with a default value of undefined . ... This allows ...
JavaScript 'this' keyword By: Rajesh P.S.In JavaScript, the this keyword is a special context-sensitive variable that refers to the current execution context or the object that a function is bound to at runtime. The value of this depends on how a function is invoked, and it plays a ...
As we know that JavaScript is adynamic type (loosely typed) language. Which, in turn, means that users needn't explicitly specify the type of data to store in a variable. The JavaScript engine will dynamically use it based on the type of data assigned to the variable. Additionally, the J...
JavaScript's double not operatoris basically double use of (!) operator. This is alogical not operator. (!!) operator converts non-Boolean to Boolean. As you know,!operator reverses the logic, i.e., it returnfalsefor!truevalue andtruefor!false. ...
JavaScript In the example above, calling the functionsayHellowith thenewkeyword would immediately create a new object that is an instance of the functionsayHello. Thethisbinding inside the function body points to the new object that was created and assigned to the variableme. ...
A brief explanation to what hoisting means in the JavaScript programming languageJavaScript before executing your code parses it, and adds to its own memory every function and variable declarations it finds, and holds them in memory. This is called hoisting....
Using JavaScript's var keyword to declare variables Because it is permissible for a variable named greeting that is created as a text string type String to change on the fly to a variable of type integer, JavaScript is known as a weakly typed language. In a strongly typed language like C++...
What is 'export default'? export defaultis a syntax used in JavaScript modules to export a single entity (be it a function, object, or variable) as thedefaultexport from a module. Consider the following example: // greeting.jsconstgreeting ='Hello, StackAbuse readers!';exportdefaultgreeting;...
JavaScript ArraysJavaScript arrays are used to store multiple values in a single variable.Example var cars = ["Saab", "Volvo", "BMW"]; Try it Yourself » JavaScript FunctionsA JavaScript function is a block of code designed to perform a particular task....