JavaScript — The Complete Beginners Guide
JavaScript — The Complete Beginners Guide to jQuery 3.0 or later
: the browser can open any file from a PDF document, and you cannot import other files into that HTML page; : it’s really only for use with Adobe Reader if your computer has support for this format ; (for example, Mac OS X 10 Snow Leopard 64 bit) JavaScript in general uses an array-based data structure, which is like CSS but more efficient because there are no duplicate elements on each line of output. If Javascript objects themselves were simple arrays they would be identical across all browsers! So what do these things mean? First, “data” refers solely specifically — not abstractly — within variable
1. JavaScript isn’t just coding
JavaScript is a full-fledged programming language, meaning it shares many characteristics with other programming languages. However, it is much easier to learn than some of these languages thanks to its simple syntax. In fact, JavaScript was designed with web developers in mind — not programmers who want to create applications for desktop computers — and makes designing websites fun and exciting!
2. JavaScript’s popularity
Because it became so popular so fast, it seems everyone wants to learn how to code JavaScript. While it is true that a lot of people use JavaScript to develop apps for their phones and tablets, almost all major website builders offer it as a feature. If someone is looking to get started with web development, they should consider learning JavaScript first before moving onto something more complex.
3. What does JavaScript do?
When we visit a website, JavaScript is at work behind the scenes, performing tasks related to our viewing experience. When we load a page, JavaScript checks if our browser supports JavaScript, and then executes any necessary compatibility code; it ensures that the site works correctly across different browsers and devices, making sure everything looks good no matter what platform you’re using. Once JavaScript has done its job, it loads the content (HTML) of a page so it can be displayed.
4. Key features of JavaScript
The following list describes four key features of JavaScript that make it so useful for designers and developers.
Functions
We’ll start with the simplest type of JavaScript function, a variable. A variable stores information in memory. It might store the name of a person, the number of months since January 1st, or the current time. Variables let us keep track of things without having to write them down over and over again. We’ll discuss variables in more detail later on.
Variables
A variable can hold a single piece of data, such as the number of seconds until Christmas Day. But what if we wanted to store several pieces of information in one place? That’s where functions come in handy. Functions let us define a special kind of variable called a function. A function lets us manipulate several pieces of data at once. If I told you a function could add two numbers together, you’d probably think it wasn’t possible. After all, numbers don’t have operations performed on them. But thanks to functions, that’s exactly what we can do. Let’s say I tell you I’m going shopping today. You could respond by saying, “Great, I’m coming with you.” Just kidding! Unfortunately, functions aren’t always used for positive purposes
5. JavaScript is a programming language that makes websites interactive. HTML helps web pages display information and hypertext links make references between them. CSS is how a website looks; it defines colors, fonts, layout, etc. A program called JAVASCRIPT controls actions performed when people interact with a page. JavaScript is a powerful tool, yet it’s not designed to replace HTML and CSS. If you’re looking to create dynamic websites without using a database, use HTML, CSS, and PHP (a server-side scripting language). If you’d rather build a database-driven site, learn SQL and use MySQL.
6. The best way to start learning JavaScript is to get a book about it. There are many books out there; some focus on syntax, others on design patterns, still others on object orientation, and some even teach you about the inner workings of JavaScript engines. 3. JavaScript was originally developed for client-side scripting — meaning that it runs inside your browser. That means you don’t have access to any data stored on your computer until after the page loads. But, as browsers started supporting XMLHttpRequest objects, developers could write programs that would run on both the client AND the server side.
7. You’ll probably hear two different dialects of JavaScript referred to as “ECMAScript”. ECMA stands for Ecma International, a group responsible for developing the standards for JavaScript. ES6 is the newer version. The older standard is called ES5.
8. In order to understand how code works at its core, you first need to understand variables. Variables store values and can be set to anything. Once a variable holds a value, it becomes a number. Numbers are useful when working with calculations, such as addition and subtraction. Strings are useful for storing text and numbers. Strings are enclosed in single quotes. You may remember strings from elementary school. We learned to use them for spelling words correctly!
9. Code is written in blocks called statements. Statements tell the computer what step to take next. If you’ve ever written a story, you know that sometimes you need to pause before moving forward. When writing code, if you want the computer to do something specific, you should place that instruction inside a statement block.
10.To help us write code effectively, we use special symbols called operators. An operator is a symbol that tells our computer how to work together with another piece of code. Operators let you combine statements into logical groups known as expressions. For example, && is an AND operator. It lets you combine two pieces of code into a single expression.
11. After you’re comfortable with basic operations, you can move on to control flow statements. These instruct the computer what to do if certain conditions are true. If…then…else is one of the simplest, which lets you jump directly to a specific line based on the outcome of a condition.
12.Functions are similar to loops. Instead of repeating instructions over and over again, you put those steps inside a function