Archive for category Lessons

Let’s Learn JavaScript • Lesson 6 • Statements and Comments

πŸ“… August 18, 2017
The JavaScript interpreter executes lines of code one by one from top to bottom. A statement is a line of code that tells JavaScript what to do.

Statements contain keywords, which are words reserved by the JavaScript language for specific instructions. These keywords, combined with user data, form the statements that comprise a script.

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Let’s Learn JavaScript • Lesson 5 • Object Primer

πŸ“… July 31, 2017
“An object? What’s that?”

JavaScript uses object-oriented programming concepts (OOP) in order to make programming easier by mirroring real-world ideas.

While it is not necessary to use objects all of the time, it helps to understand what an object is because JavaScript views various parts of a web page and browser as objects.

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Let’s Learn JavaScript • Lesson 4 • Planning a Script

πŸ“… July 24, 2017
A script usually refers to a short program executed by an interpreter. Python, Perl, and JavaScript are examples of interpreted scripting languages. When we code client-side JavaScript, we write scripts that run in web browsers.

Scripts are intended to be lightweight and short in order to consume fewer system resources than full-fledged applications. This way, pages render faster in a web browser.

The purpose of using JavaScript in a web page is to make the page interactive either with the user directly or with a web server. Interactive pages are dynamic — page contents can change as the page is loaded or while the page is being viewed. JavaScript can access and modify page content and react to user input, such as button clicks or form entry. The result is a web page that feels more alive compared to static content that does not change.

No matter how simple or fancy a script might be, we need to plan before writing any code.

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Let’s Learn JavaScript • Lesson 3 • Beginning JavaScript

πŸ“… July 19, 2017
Continuing from the exciting Greetings Universe! HTML file we wrote in the previous lesson, let’s add some JavaScript to show a popup dialog and write text to the page.

 

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Let’s Learn JavaScript • Lesson 2 • Basic HTML 5

πŸ“… July 14, 2017
Client-side JavaScript requires a knowledge of HTML, so this lesson will focus on building a minimal HTML 5 file that we can use for writing JavaScript.

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Let’s Learn JavaScript • Lesson 1 • Introduction

πŸ“… July 13, 2017
β€’ Have you ever submitted a form only to find that some fields will filled incorrectly with red borders? That is JavaScript in action.

β€’ Have you scrolled through a list of images and noticed new images appear? That is JavaScript trying to make life easier for you while conserving bandwidth.

β€’ Have you ever thrown up your hands in anger as annoying popups littered your desktop with mind-jarring, blinking ads accompanied by new browser windows that expand to fullscreen in order to advertise an online survey? That is JavaScript being used to aggravate in hopes that you will part with your money.

JavaScript is a full-featured programming language that produces web pages whose content can change when certain conditions are met. If you have ever wanted to learn how to perform this mysterious magic in JavaScript, then here is the first lesson that introduces the background of this fun language.

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Binary Lesson 17 – Parity

πŸ“… March 4, 2015
lesson17The word parity originates from the Latin word par, meaning equal. Take the sport of golf, for example. A hole on a golf course is usually assigned a par number. If you sink the golf ball into the hole with the same number of strokes as the par, you are said to be on parΒ — equal to the number of expected strokes.Β If you expend more strokes than the par, then you need practice, and you should probably try again.

An identical strategy applies to computers. Parity is an early form of error detection often used with serial communications, such as modems and serial ports, for example. An extra bit is appended to each data byte to make the total number of 1 bits even or odd. This extra bit, called the parity bit, is separate from the data byte, and it does not contain data information. It is only used to make the total number of 1 bits even or odd.

There are two main types of parity: Even parity and odd parity. Both operate in the same manner aside from the evenness or oddness.

This lesson focuses on 8-bit data even though the concept can apply to any number of data bits, such as 7-bit ASCII.

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