Section Review of Making Your First Web App

Section Review of Making Your First Web App

Lesson Details:
July 10, 2020


I: Introduction

A: Introduction to programming coding languages

What are programming languages?

Programming languages are used to write instructions for computers. They are the medium that programmers use to write computer programs.

Programming languages can be as simple as writing an algorithm on paper or as complex as writing a program that controls a space shuttle. The key is that they give you a way to write instructions that can be understood by a computer.

There are hundreds of different programming languages out there, from very simple ones like Logo, which is a language for kids, to very complex ones like Java, which is a language for building web apps. But what do all these different programming languages have in common?

II: Body

A: Section review of making your first web app

What do you need to make a web app?

You will need a computer with an internet connection and a programming language. There are lots of programming languages out there, but I’m going to talk about just one of them – JavaScript.

JavaScript is a programming language that is used to create web apps. Web apps are programs that run from a computer, but instead of running on a desktop, they run from a website. This means that anyone with a computer and an internet connection can access your program. This is great if you want your work to have a wide audience – the more people you can reach, the better!

How do you make a web app?

You write code in your chosen programming language. You then run this code inside a web browser (the program that lets you browse the internet). A web browser will display your code as text and images on a webpage. This is called compiling. By looking at this webpage, users can interact with your program and run it without needing any special software installed on their computer. This is called executing. Your program works like a stand-alone application: it runs by itself and users can stop and start it whenever they want. Take a look at this short video to see how web apps work: https://www.youtube.com/watch?v=Dyf2aT39Fug&t=37s

How do you get started?

To get started, you will need three things:

A computer with an internet connection A web browser A programming language (like JavaScript) A web browser is the program that lets you browse the internet and see pages like this one. Lots of websites use HTML to display information and present content to users. Browsers also let you interact with the website – clicking links and filling in forms – which sends information back to the website so it can respond to what you have done. Most computers come with a web browser already installed, but if yours doesn’t, you can download one here. HTML stands for HyperText Markup Language. It’s the language used to make up websites. HTML uses tags to define the structure of a page and separate different parts of content, like text and images. Everything on this page has been written using HTML, including the words on the screen, the images below, and even this paragraph! Browsers read HTML files and show them to users on their screens. JavaScript is a programming language that lets you create interactive web apps. It works by running code inside your web browser. Code is run line by line, starting at the top of the file and working downwards. When it reaches the end of the file, it starts again at the top line of the next one, until it gets to the bottom of your program. The last line of your program executes first because it sits at the top of the file. It might sound confusing but if you just follow along with some examples it should become clearer! To learn more about how JavaScript works, take a look at this video: https://www.youtube.com/watch?v=kLXWmQI8u0M&t=49s Once you know which language you want to use, downloading it is easy. All you need to do is go to its website, where you can find instructions on how to install it on your computer. Installing new software on your computer might seem complicated, but most operating systems (Windows, Mac OS X or Linux) include an option that makes it really easy for you to install software without doing any technical stuff! Once you’ve downloaded your chosen programming language, try following along with some examples like these: https://www.codecademy.com/courses/learn-javascript/lessons/hello-world/exercises/hello-world-2 If you already have experience with another programming language like Python or Java, JavaScript will feel familiar because most programming languages share similar concepts and ideas. Getting started with JavaScript is easy because most computers come with a JavaScript interpreter (a program that reads and runs your code) installed already! To run your own .js files with JavaScript on your Windows or Mac computer, you just need to open up your command prompt or terminal window (look for these in your programs list), navigate to your project folder (this should be something like C:UsersDocumentsMy Projects), and type node filename.js -o filename.html -e filename.htm You can find out more about how to install Node here: https://nodejs.org/en/download/ To test your code and see how it works in real life, open up Chrome and visit http://localhost:8080/. This website runs off your computer because Chrome understands JavaScript and lets you run Node applications locally (on your own computer). To install Node on MacOS or Linux just follow the instructions here: https://nodejs.org/en/download/ To test your code visit http://localhost:8080/. This website runs off your computer because Chrome understands JavaScript and lets you run Node applications locally (on your own computer). Use CTRL + C to stop running Node applications on MacOS or Linux — or — close the Terminal window and restart Node (type node filename.js -o filename.html -e filename.htm) on Windows — or — press “Ctrl + Z” then “Ctrl + C” on Windows For more tutorials visit: https://www.codecademy.com/tracks/javascript

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