Learn javascript from scratch for free
part 1
JavaScript Basics
1. The 10 Concepts That are The Same In Every Programming Language
There are 10 concepts in JavaScript that are the same in nearly every programming language. In this lesson, we’ll go through some of them namely: Events, Comments, Print, Variables, Data Types, Conditionals, Functions, Arrays, Concatenation and Debugging. In the lesson, you'll get a preview of the first application you are going to build as you learn these concepts. Exciting times ahead!2. JavaScript Events
JavaScript in the browser uses an event-driven programming model. An event is a signal that something has happened. Examples of events are the page completing loading, a user clicking on a button, hovering on an element, typing into an input box, submitting a form, etc. JavaScript enables you to respond to events using Event Handlers. You can attach an event handler to the HTML element for which you want to respond to when a specific event occurs.3. Comments in JavaScript
In computer programming, comments are annotations in the source code of a computer program that are added with the purpose of making the source code easier for humans to understand, and are generally ignored by compilers and interpreters. You should add useful comments to your code to explain what the code does to make it easier for another programmer (or your future self) to go through the code and understand what it's doing and how it works.4. Print
At some point, you are going to have to write code that displays some output to the user. In JavaScript, you can write to the DOM (Document Object Model—we'll cover the DOM later, but basically, what's written to the DOM determines what's shown in the browser) using the document.write() function.5. Variables
In programming, a variable is a storage location paired with an associated symbolic name, used to store information to be referenced and manipulated in a computer program. You can think of variables as containers that hold information. Their sole purpose is to label and store data in memory, which can then be used throughout your program.6. Concatenation
Concatenation (or concat for short) is a way of combining the text of two strings together into a variable. Watch the example in this video—as it's much easier to understand when you see it in action.7. Datatypes
In JavaScript, there are two different kinds of data: primitives, and objects. There are seven primitive data types: Boolean, Number, String, Null, Undefined, Symbol and bigint (newly introduced). In this lesson, we'll focus on two of these, i.e. Strings and Numbers.8. Functions
In programming, a function is a named section of a program that performs a specific task. A function groups together one or more program statements that perform some operation(s) and optionally return a value.9. Conditionals
Often a computer program must make choices on which way to proceed. Conditional statements are features of a programming language which perform different computations or actions depending on whether a specified boolean condition evaluates to true or false.10. Arrays
An array is a data structure used to store multiple values in a single variable. In some programming languages, arrays can only hold values of the same type, but not in JavaScript. In JavaScript, you can have values of different types in the same array.11. JavaScript Debugging
One thing you can be sure of when coding: you will encounter bugs. Let's learn how to deal with them. In this lesson, we look at various tools available to help us in debugging our code. You will learn how to log out messages to your browser's console and how to use the Developer Tools available in your browser to inspect and identify issues in your code.12. Steal this code: Happy Hour App
In this lesson, you'll download a completed JavaScript application, and then we'll learn together by breaking it! Yep, sometimes hacking around a completed app is the best way to learn. You'll be challenged to complete some tasks on your own to test what you've learned so far.VISIT FOR MORE COURS
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