Mar
17
PBS 11 of X – Tables
Filed Under Software Development, Computers & Tech on March 17, 2016 | 2 Comments
Finally, after many months of making Allison wait, it’s time to look at tables on web pages. We’ll start by describing the HTML markup for tables, and then look at how to style them with CSS.
Remember – tables are for one thing, and one thing only – displaying tabular data!
Apr
1
PBS 12 of X – Introducing JavaScript
Filed Under Computers & Tech, Software Development on April 1, 2016 | 7 Comments
With this instalment we’re starting into a whole new phase of the series. We’ve looked at using HTML to define the structure of an HTML document, and then we moved on to looking at CSS for defining the look of an HTML document, and now we’re going to move on to JavaScript to add interactivity to HTML documents.
Learning the basics of JavaScript, and learning how to connect JavaScript into the browser environment are two very different tasks, so, we’re going to separate them. We’ll start by learning some JavaScript fundamentals in a JavaScript playground I’ve created. Only when we know enough JavaScript for the mechanics of the browser’s JavaScript integration to make sense will we move tackle the so-called DOM, and the browser event model.
Apr
9
PBS 13 of X – JS Conditionals
Filed Under Computers & Tech, Software Development on April 9, 2016 | 1 Comment
In the previous instalment we got our first taste of JavaScript. We learned about variables, literal data types, and some basic string and arithmetic operators. In this instalment we’re going to focus on booleans. We’ll look at how non-boolean values get converted to booleans when needed (e.g. is 'boogers'
true
or false
?), we’ll learn about some comparison operators that result in boolean values, and we’ll learn about some logical operators. At that stage we’ll have all the knowledge we need to learn about our third fundamental programming concept – branching.
May
12
PBS 14 of X – JS Loops & Arrays
Filed Under Computers & Tech, Software Development on May 12, 2016 | 1 Comment
At this stage we’ve learned about three of the key components common to just about every programming language, and how they’re implemented in JavaScript – variables, operators, and branching. Now it’s time to add two more – arrays, and loops.
Arrays store a list of related data in a single variable, and loops allow us to apply the same action over and over again. To process an arbitrarily long array, you need some kind of iteration, and loops are the simplest way of achieving that.
May
27
PBS 15 of X – JS Functions
Filed Under Computers & Tech, Software Development on May 27, 2016 | 1 Comment
At this stage we’ve learned about five key components to any programming language, and how they are implemented in JavaScript – variables, operators, branching, arrays, and loops. Now it’s time to add another – functions.
A function is a collection of statements that is given a name so it can be easily re-used. We’ve already used functions, but without knowing that’s what we’ve been doing.
Jun
8
PBS 16 of X – JS Callbacks
Filed Under Computers & Tech, Software Development on June 8, 2016 | 1 Comment
In the previous instalment we introduced the concept of JavaScript functions. We learned how to all existing functions, and how to create out own.
In this instalment we’re going to take our understanding of functions to the next level. The techniques we encounter today would be considered advanced techniques in most other languages, and you could spend years developing in Java and never encounter an anonymous function. However, because of how JavaScript is integrated into HTML documents, these techniques are considered fundamental in JavaScript, and anonymous functions are a dime a dozen!
Before we delve into anonymous functions, we’ll start by taking a deeper look at how JavaScript deals with function arguments.
Jun
23
PBS 17 of X – JS Objects
Filed Under Computers & Tech, System Administration on June 23, 2016 | 4 Comments
At this stage in the series we have made very good progress towards understanding the core JavaScript language. However, there is still one very important piece missing – objects. We have mentioned them in passing in almost every instalment, and each time, we put them off until later. We finally remedy that in this instalment.
Jul
6
PBS 18 of X – JS Miscellany
Filed Under Computers & Tech, Software Development on July 6, 2016 | 4 Comments
We’ve now covered most of the core JavaScript language. We’ve learned that variables can store literal values, or references to objects. We’ve learned there are three types of literal values – numbers, booleans, and strings. We’ve learned about operators. We’ve learned about conditionals. We’ve learned about loops of various sorts, and we’ve learned about objects. We’ve learned that in JavaScript, arrays are implemented as objects with the prototype Array
, and that functions are also implemented as objects.
Before we can leave the playground and head off into the world of the browser, we just have a few more loose ends to tie up, which we’ll take care of in this instalment.
Now that we know about objects, we need to re-visit the arguments
object present in every JavaScript function. We need to take a detailed look at the typeof
operator, and we need to look at some built-in objects and functions JavaScript provides.
We also need to look at how JavaScript handles regular expressions, and finally, we need to introduce the concept of exception handling.
Jul
14
PBS 19 of X – Some JavaScript Challenges
Filed Under Computers & Tech, Software Development on July 14, 2016 | 6 Comments
While recording instalment 18 of the Programming by Stealth series, I promised Allison some challenges to help listeners test and hone their understanding of the core JavaScript language. Since we’ve now covered pretty much the whole language in the series, it’s the perfect time to pause and consolidate that knowledge.
These challenges are designed to be run in the PBS JavaScript Playground. You may also find the PBS JavaScript cheatsheet helpful.
Sep
1
PBS 20 of X – JS in the Browser
Filed Under Computers & Tech, Software Development on September 1, 2016 | 4 Comments
After six instalments, it’s finally time to bring our JavaScript knowledge into the web browser. We’ve already learned that HTML is used to specify the structure of a web page, and CSS to specify its appearance, so where does JavaScript come in? JavaScript’s primary use on the web is to add interactivity and/or automation of some kind. For example, clicking on something could cause the page to change in some way, or, icons could be automatically injected into the page to mark links that open in new tabs as being different to other links.
A key point to note is that HTML, CSS, and JavaScript are all so-called client-side technologies. It’s the web browser doing the work, not the web server. The web server simply delivers the HTML, CSS, and JavaScript code to the browser as text, just like you type it, and the browser then interprets that code and turns it into the web page you see and interact with.