Introduction to Backend Development

Backend development is like building the behind-the-scenes part of a website. It's like making the walls and plumbing of a house - you don't see it, but it's necessary for everything else to work. With backend development, you create the parts of a website that allow it to do things like store data and show different pages.

Table of Content

• Overview
• History of Backend Development with Javascript
• Javascript Fundamentals
• Variables in JavaScript
• Common mistakes to avoid when using variables in JavaScript
• What is a javascript function?
• Scopes in Javascript
• Difference between let, var and const in Javascript
• Understanding the concept of hoisting in JavaScript
• Class Materials
• Conclusion
• Assignment

Overview

Backend development refers to the creation and management of the server-side of web applications. It involves the development of server-side logic, database integration, and ensuring that the server-side of the application runs smoothly. Backend development is critical to web development because it is responsible for the functionality of the web application, including the management of data and user authentication.

Backend development is essential in web development because it provides the server-side of web applications with the necessary functionality to work effectively. Backend developers create, manage, and maintain the logic that ensures that the server-side of the application can communicate with the front-end.

History of Backend Development with Javascript

JavaScript is a powerful programming language that has gained immense popularity over the years. Initially, JavaScript was mainly used for front-end web development. However, with the introduction of Node.js in 2009, JavaScript could be used for backend development as well. Node.js is an open-source, cross-platform runtime environment that enables developers to build server-side applications using JavaScript.

Javascript Fundamentals

Overview of JavaScript as a programming language

JavaScript is a popular, high-level, and dynamic programming language used to create dynamic web applications. It is a multi-paradigm language that supports both functional and object-oriented programming paradigms.

Characteristics of Javascript

JavaScript is a client-side scripting language that can be executed on a user's browser. It is used for creating dynamic web content and animations, as well as developing server-side applications. JavaScript has a simple syntax, making it easy to learn and use for beginners. It also supports asynchronous programming, allowing for the creation of non-blocking, responsive applications.

How Javascript is used in web development

JavaScript is used in web development for creating dynamic web applications, client-side validation, and event handling. It can also be used for server-side programming, thanks to the introduction of Node.js. JavaScript is also used for data visualization, animation, AI, game development and much more.

Variables in JavaScript

Definition of variables

A variable is a named storage location in computer memory that holds a value. In JavaScript, variables are used to store data, and they can be accessed and manipulated throughout the code.

Declaring and assigning variables in JavaScript

In JavaScript, variables can be declared using the var, let, and const keywords. The var keyword is used to declare global variables, while the let and const keywords are used to declare block-scoped variables.

let firstName = "John"
let lastName = "Doe"

let fullName = firstName + " " + LastName

Rules for naming variables in JavaScript

• JavaScript variable names must start with a letter, underscore, or dollar sign.
• They cannot start with a number or contain spaces.
• Variable names are case-sensitive, and it is best practice to use descriptive names that reflect the purpose of the variable.

let a = "Variable" // Not descriptive enough

let 2hello = "Variable" // This will throw an error

let fullName = "John Doe" // This is correct (It is adviced to stick to camel case naming pattern like this)

Common mistakes to avoid when using variables in JavaScript

Some Common mistakes when using variables in JavaScript include:

• Forgetting to declare the variable before using it
• Reusing variable names without declaring them again
• Overwriting or reassigning a variable unintentionally
• Using inappropriate names for variables
• Not initializing a variable before using it

What is a Javascript function?

A JavaScript function is a block of code designed to perform a particular task. A JavaScript function is executed when "something" invokes it (calls it). For example, a function can be invoked when an event occurs, such as when the user clicks a button.

Regular functions vs Arrow Functions

Regular functions are written with the function keyword, while arrow functions are written with the '=>' syntax. Regular functions have their own 'this' and 'arguments' binding, while arrow functions use their parent's 'this' and 'arguments' binding. Arrow functions are also more concise than regular functions. Regular functions are hoisted, while arrow functions are not. Lastly, arrow functions cannot be used as constructors.

//regular function declaration
function greeting() {
  alert("Hello World!");
}

//arrow functions declaration
const hello = () => {
  alert("Hello World!");
}

// Invoke the function
greeting();
hello();

Scopes in JavaScript

Definition of scopes

Scope in JavaScript refers to the current context of the code being executed. Generally, the context in which the code is written determines what variables and functions are accessible and what is not.

For example, if you have a variable defined outside of any function, it is in the global scope and is accessible from anywhere in the code.

var x = "Hello World";

console.log(x); // returns "Hello World"

However, if you define that same variable inside of a function, it is then only accessible inside of that function.

function myFunction() {
    var x = "Hello World";
}

console.log(x); // returns undefined

Types of scopes in Javascript

Global scope refers to variables that are accessible from anywhere in the program. Local scope refers to variables that are only accessible within a specific function or block of code.

It is best practice to use local scope as much as possible to avoid naming conflicts and improve performance.

Best practices for using scopes in JavaScript

Best practices for using scopes in JavaScript include:

• Using local scope as much as possible to avoid naming conflicts
• Avoiding the use of global variables as much as possible to improve security and performance
• Declaring variables at the beginning of the function or block of code to avoid hoisting issues
• Using let and const instead of var to declare block-scoped variables

Difference between let, var and const in Javascript

In JavaScript, let, var, and const are all used for variable declaration.

Let is the modern way of declaring variables. Variables declared with let have block scope, which means they can only be used within the block they are declared in. They can be reassigned, but they cannot be redeclared.

Var is an older way of declaring variables. Variables declared with var have function scope, which means they can be used anywhere within the function they are declared in. They can be reassigned and redeclared.

Const is used to declare constants, which are variables that cannot be reassigned. Constants have block scope, just like let variables. Unlike let variables, constants cannot be reassigned.

Understanding the concept of hoisting in JavaScript

Hoisting is a JavaScript behavior where variable and function declarations are moved to the top of their respective scopes. This means that variables can be declared after they are used, and functions can be called before they are declared.

greeting() //Calling the function before it is created

function greeting() {
	return "Hello World"
}

Class Materials

Conclusion

Recap of the importance of backend development with JavaScript

Backend development is crucial to web development because it provides the necessary functionality to make web applications work effectively. With Node.js, JavaScript can be used for server-side programming, making it a versatile language for web development.

Final thoughts on JavaScript basics, variables, and scopes

JavaScript is a powerful programming language that is widely used for web development. Understanding the basics of JavaScript, including variables and scopes, is essential for anyone interested in becoming a backend developer. With practice and perseverance, beginners can become proficient in JavaScript and take on complex web development projects.

Here are some recommended resources for beginners interested in learning about backend development with JavaScript and JavaScript basics, variables, and scopes:

1. MDN Web Docs: JavaScript - This is a comprehensive resource for learning JavaScript, with tutorials, documentation, and examples.
2. Node.js Documentation - Node.js is a popular backend development framework that uses JavaScript, so understanding Node.js is essential for backend development with JavaScript.

These resources should provide a solid foundation for beginners interested in learning about backend development with JavaScript and JavaScript basics, variables, and scopes.

Assignment

We recommend google docs for your submissions, ensure the links are set for public view.

Your Assignment ID

[be01]

Assignment Question

• What is backend development?
• What is the purpose of backend development with JavaScript?
• What are the advantages of using JavaScript for backend development?
• What are the basic concepts of backend development?
• What technologies are commonly used for backend development with JavaScript?

Assignment Deadline

17th March, 2023

How to submit your assignment

Simply use the "/submit" command on discord, select the assignment option, then enter your name, email, assignment id (be01) and assignment link to submit your assignment.

Marvelous Solomon

Software Engineer | AI/NLP Engineer | Solutions Architect | Mentor

solomonmarvel97Publications