Some JavaScript content delivery networks (CDN):
JavaScript scope refers to the context in which variables, functions, and objects are defined. It determines the accessibility and visibility of these elements within the code. Understanding scope is crucial for writing maintainable and error-free JavaScript code.
JavaScript has three types of scope:
JavaScript collections refer to data structures in the JavaScript programming language that are used to store and manipulate collections of values or objects. These collections provide various ways to organize and access data efficiently. There are several built-in collection types in JavaScript, and developers can also create custom collections as needed.
In JavaScript, collections like arrays, objects, sets, and maps are built-in language features. They are part of the core JavaScript language and do not require any external extensions or libraries to use. JavaScript provides these data structures as fundamental constructs for working with and organizing data within your programs.
JavaScript's forEach() function executes a function on every element in an array. However, since forEach() is a function rather than a loop, using the break statement is a syntax error.
Variables declared with the const maintain constant values. const declarations share some similarities with let declarations.
Variables are containers for storing data in JavaScript. JavaScript variables can be declared in 4 ways:
var: Declares a variable with function scope. It's less commonly used in modern JavaScript due to its potential for scope-related issues.
let: Declares a variable with block scope, limiting it to the block or statement in which it's defined. It allows reassignment.
const: Declares a constant variable with block scope. Once assigned, its value cannot be changed.
Choosing between them depends on your needs for variable scope and mutability. const is preferred when you don't intend to change the variable's value, while let is suitable for variables that need to be reassigned. var is generally avoided in modern JavaScript due to its quirks related to scope.
We'll discuss the differences in Scope, Redeclaration, and Hoisting.
let is now preferred for variable declaration. It's no surprise as it comes as an improvement to var declarations. It also solves the problem with var that we just covered. Let's consider why this is so.
Before the advent of ES6, var declarations ruled. There are issues associated with variables declared with var, though. That is why new ways needed to declare variables to emerge.
JavaScript is a versatile and widely-used programming language, known for its ability to add interactivity and dynamic behavior to web pages. Key features include its simplicity, support for both front-end and back-end development, asynchronous capabilities, and a vast ecosystem of libraries and frameworks, making it essential for modern web development.
Axios is a popular JavaScript library that simplifies HTTP requests, making it easy for beginners to interact with web services and APIs. With a simple and intuitive syntax, Axios provides a clean way to handle asynchronous tasks in web development. Whether fetching data or sending requests, Axios streamlines the process, enhancing the efficiency of frontend development.
Make Axios send cookies in its requests automatically.
You can use the withCredentials property.
axios.get(BASE_URL + '/todos', { withCredentials: true });Also it is possible to force credentials to every Axios requests
axios.defaults.withCredentials = trueOr using credentials for some of the Axios requests as the following code
const instance = axios.create({
withCredentials: true,
baseURL: BASE_URL
})
instance.get('/todos')In JavaScript, an array is a special object that provides a way to store and organize data. It is a linear, ordered collection of elements, and an index can access each element. The array object in JavaScript comes with various built-in methods for manipulating and working with arrays.
The some() method of Array instances tests whether at least one element in the array passes the test implemented by the provided function. It returns true if, in the array, it finds an element for which the provided function returns true; otherwise, it returns false. It doesn't modify the array.
Reference: Array.prototype.some() - JavaScript | MDN (mozilla.org)
JavaScript functions are reusable blocks of code that perform specific tasks. Defined using the function keyword or as arrow functions, they can accept parameters and return values. Functions enhance code organization, modularity, and reusability, allowing developers to execute the same logic multiple times throughout a program with ease.