How to Start Learning JavaScript

Whether you’re a beginner looking to get your feet wet in the world of coding, or a seasoned developer looking to add another language to your toolkit, the JavaScript scripting language is a great choice.

JavaScript is used on almost every website on the Web. Thanks to serverless computing, it can even be used as a language for backend programming in the cloud. It has a simple syntax that’s easy to learn, even for beginners. And there are lots of resources from a booming community of fellow developers.

But how can you get started learning it? If you’re not sure where to begin, we’ve written this post for you. We’ll cover the basics of the JavaScript scripting language and provide resources and tips for you to continue learning on your own.

Where to Get Started Learning Python

Familiarize yourself with the basics of JavaScript. This will help you understand the foundations of programming as a whole, and make it easier for you to learn the language If you’re not sure where exactly to start, don’t worry! We’ll go over them in a minute.

Practice, practice, practice. (And then practice some more!) It shouldn’t really come as a surprise that the best way to learn any programming language is to write code and keep breaking things until you get them right. Start by working through some beginner-level exercises and challenges to get a feel for how JavaScript works.

Learn about the Document Object Model (DOM). The DOM is an essential part of web development with JavaScript. It represents the structure of an HTML document as a tree of objects — and allows you to manipulate the content and layout of a web page. If you want to have anything to do with web development, knowing how to the DOM works is essential.

Explore more advanced concepts. Once you have a solid foundation in the basics of JavaScript, you can start learning more advanced topics such as Object-Oriented Programming (OOP), asynchronous programming, and working with APIs.

Reflect and keep learning. Reflect on what you have learned and identify any areas where you need further practice or clarification. Consider setting specific goals for your continued learning and practice in JavaScript.

There are many resources available online to help you learn JavaScript, including online courses, tutorials, and documentation. It’s important to find a learning resource that works best for you and to be patient and persistent as you learn.

With practice and dedication, you can master JavaScript on your own terms!

Get to Know the Basics of JavaScript

Start by getting to know JavaScript’s syntax, operators, variables, data types, and control structures.

Syntax

Like every other programming language, JavaScript has a set of rules for how code should be written and formatted. To master JavaScript, start with its syntax.

This includes writing statements, using whitespace, knowing where to have commas, colons, and semicolons, and adding comments to your code. It’s important to familiarize yourself with JavaScript’s syntax so you write code that doesn’t throw errors and that’s easy to debug.

Here’s where to start:

Statement: A statement is a line of code that performs a specific action or task. In JavaScript, statements are typically terminated with the semicolon character (;).

Comments: In JavaScript, comments start with // and end with a new line.

// This is a comment

Code blocks: As a language, JavaScript uses a syntax similar to C. It uses curly braces ({}) to denote blocks of code, and semicolons (;) to terminate statements.

Case-sensitivity: JavaScript is case-sensitive, which means that variable names, function names, and other identifiers are treated as different depending on the capitalization.

// This
var myVar = "Variable content";

// Is different from this
var myvar = "Variable content";

Variable declarations: Variables in JavaScript are declared with the var, let, or const keywords.

// Variable with "var" keyword
var myFirstVar = 1;

// Variable with "let" keyword
let mySecondVar = 2;

// Variable with "const" keyword
const myThirdVar = 3;

Function declarations: Functions in JavaScript are declared with the function keyword, and they can be called using their name followed by a set of parentheses.

// Declaring a function
function logToConsole(text) {
   console.log(text);
}

// Calling a function
logToConsole("Hello, world!");

You can nest functions in JavaScript. This means that you can define a function inside another function. For example:

function outerFunction() {
  function innerFunction() {
    // Code for the inner function goes here
  }
  // Code for the outer function goes here
}

JavaScript has a number of built-in functions that you can use right out of the box in your statements and functions.

Build-in objects: JavaScript also has a number of built-in objects, such as the Math object and the Date object, which provide access to various mathematical functions and date and time functions, respectively.

These are just a few of the key points to keep in mind when it comes to JavaScript syntax. As you continue learning JavaScript, you’ll have the opportunity to learn more about the specific syntax rules and conventions of the language.

Operators

JavaScript has a number of operators that you can use to perform operations on variables and values. These include:

• Arithmetic operators: Just like math, this type of operators perform mathematical operations on numerical values:
  • The addition operator (+) for adding values together
  • The subtraction operator (-) for subtracting one value from another
  • The multiplication operator (*) for multiplying two values
  • The division operator for dividing two values (/)
  • The modulus operator for returning the remainder of a division (%)
• Comparison operators: These operators compare two values and return a Boolean value indicating whether the comparison is true or false:
  • The equal operator (==) for determining if two values are equal
  • The strictly equal operator (===) for determining if two values are equal and of the same data type
  • The not equal to operator (!=) for determining if two values are not equal
  • The greater than operator (>) for determining if one value is greater than the other
  • The less than operator (<) for determining if one value is less than the other
  • The greater than or equal to (>=) operator for determining if one value is greater than or equal to the other
  • The less than or equal to (<=) operator for determining if one value is less than or equal to the other
• Logical operators: These operators perform logical operations on Boolean values (true or false):
  • The logical AND operator (&&) returns true if both operands are true)
  • The logical OR operator (||) returns true if at least one operand is true)
  • The logical NOT operator (!) negates a Boolean value
• Ternary operator: The ternary operator (? :) allows you to perform a conditional operation
• Typeof operator: The typeof operator (typeof) returns a string indicating the type of a value.

Variables

Like every other programming language, JavaScript lets you declare variables and store information in them. You can think of variables as containers that hold a value, such as a number, a string of text, or an object, in the device’s memory.

There are three ways to define variables in JavaScript: var, let, and const.

// Global "var" variable
var name = "John Doe";

// Function-scoped "var" variable
function logName() {
   var name = "John Doe";
   console.log(name);
}

var is the oldest and most well-known way to declare a variable in JavaScript. It has been a part of the language since the beginning, and it is still widely used today. var variables are function-scoped, meaning they are accessible within the function in which they are defined, as well as any nested functions. They can also be accessed globally, if they are defined outside of any function.

// Block-scoped "let" variable
let name = "John Doe";

let is a newer keyword that was introduced in the ECMAScript 2015 (ES6) specification. It is similar to var in that it allows you to declare a variable and assign it a value, but let variables are block-scoped, meaning they are only accessible within the block of code in which they are defined.

// Block-scoped "constant" variable
let name = "John Doe";

const is also a newer keyword that was introduced in the ECMAScript 2015 (ES6) specification. It is used to declare a read-only variable that cannot be reassigned once it has been defined. Like let variables, const variables are block-scoped.

Generally, it’s recommended to use const whenever possible, as it helps prevent accidental reassignments and makes your code easier to understand and maintain. let can be used when you need to reassign a variable, and var can be used in situations where you need to declare a variable when you need to access a variable globally.

Data Types

The data type of a variable determines what type of data the variable can hold. For example, a variable with a number data type can hold numerical values, while a variable with a string data type can hold a sequence of characters.

Primitive data types:

1. Number: This data type represents any numeric value, including integers and floating-point numbers.
2. String: This data type represents a sequence of characters, such as a word or phrase. Strings are typically enclosed in single or double quotes.
3. Boolean: This data type represents a true or false value.
4. Null: This data type represents the absence of a value or a null reference.
5. Undefined: This data type represents the absence of a value or a variable that has not been assigned a value.
6. Symbol: This data type was introduced in the ECMAScript 2015 (ES6) specification and represents a unique and immutable primitive value.

Complex data types:

In JavaScript, there are two main complex data types: Object and Array.

An Object is a collection of key-value pairs that can represent almost any data structure. Objects are useful for storing and organizing data in a structured way. They are created using curly braces {}, and the keys and values are separated by a colon :.

const person = {
  firstName : "John",
  lastName : "Doe",
  age : 30
};

In this example, person is an object with three properties: firstName, lastName, and age.

Now suppose we want to add hobbies for that person. We can do so by adding an Array to the person object:

const person = {
  firstName : "John",
  lastName : "Doe",
  age : 30,
  hobbies : ["reading", "coding"]
};

An Array is an ordered list of values. Arrays are created using square brackets [], and the values are separated by commas.

In this example, hobbies is an array with two values: reading and coding. Arrays are useful for storing lists of data and can be accessed using an index, which is a zero-based numbering system. For example, to access the first value in the numbers array, you start at 0. To access the second, you’d access 1, and so on.

Both Object and Array data types are complex because they can contain multiple values and can be nested inside each other. They are an important part of the JavaScript language and are often used to store and manipulate data in a variety of applications.

Control Structures

JavaScript control structures are statements that allow you to control the flow of your program. They allow you to execute different blocks of code based on certain conditions or to repeat a block of code multiple times.

if statements allow you to execute a block of code if a certain condition is true.

// Determines if x is greater than y
function compareXAndY(x, y) {
  if (x > y) {
    console.log("x is greater than y");
  } else {
    console.log("x is not greater than y");
  }
}

compareXAndY(5, 10);

for loops allow you to execute a block of code multiple times, using a counter variable to keep track of the number of iterations.

// Logs numbers 1 through 9 in the console
for (let i = 0; i < 10; i++) {
  console.log(i);
}

while loops allow you to execute a block of code multiple times as long as a certain condition is true.

// Logs numbers 1 though 9 in the console
let i = 0;
while (i < 10) {
  console.log(i);
  i++;
}

do...while loops are similar to while loops, but the block of code is always executed at least once, and the condition is checked at the end of each iteration.

// Logs numbers 1 though 9 in the console
let i = 0;
do {
  console.log(i);
  i++;
} while (i < 10);

switch statements allow you to execute different blocks of code based on the value of a variable.

// Logs "The color is orange." in the console
const color = "orange";

switch (color) {
  case "orange":
    console.log("The color is orange.");
    break;
  case "black":
    console.log("The color is black.");
    break;
  default:
    console.log("The color is another color.");
    break;
}

In Summary

Learning a new programming language is never easy. But if you get started on the right foot, it isn’t that hard, either. We hope we’ve helped you get some of the most foundational concepts of JavaScript, and we wish you the best of luck on the rest of your journey!