Javascript

Functions are repeatable blocks of code. They are fundamental to most programming languages and allow you to build applications with reusable code that can be called with different arguments. The best way to explain functions is through an example. Suppose you wanted a quick way to calculate how much your bill would be with tip (assume for this example the bill amount includes tax). → Try it out Create two files called index.html and script.js and enter the code below into each. Alternatively, if you followed along in the previous lesson, use the existing script.js file and replace its content with code below. ...

Often in programming, we need to carry out similar instructions a number of different times. Loops help reduce redundant code and let you quickly offload repetitive tasks to the computer. In JavaScript there are several types of loops. In this lesson we are going to examine while, do while, and for loops. While and Do While loops As their names suggest, while and do while loops carry out a number of tasks ‘while’ a certain condition is true. Take for example the need to display a series of numbers each incrementing by 1 until it we reach a certain limit (10). This could be carried out by writing the following code: ...

A while ago I wrote an article called Using jQuery.AJAX() to Retrieve Sample JSON Data. Since this time I’ve been slowly using more and more native JavaScript to get things done, so I thought it was time to revisit this concept using the fetch() API. It has been very convenient over the years to use jQuery to simplify tasks that otherwise would have been more challenging to write in native JavaScript. Since ES6 has become pretty much mainstream nowadays, it is safe to take advantage of some of the features and benefits it brings. ...

Conditional statements (commonly called if statements) provide a way for JavaScript to make decisions and run specified code based on a set of criteria. In JavaScript, the criteria or condition is surrounded in parenthesis and the resulting code to run is contained in a block. Up until now, we have been examining single line statements. In JavaScript, a block of code is surrounded by curly braces. Let’s look at an example. ...

JavaScript provides different kinds of operators which enable us to perform actions on given values or variables used in our code. As you develop more complex code, you will come to rely on operators for performing the various functionally you are building. Before we dive into operators, let’s clear up a couple of fundamental programming terms, statements and expressions. A statement is a line of code or action that consist of values, variables, and operators. In the last lesson you created several statements that assigned values to variables using the assignment = operator. Statements can set values but do not become values themselves. Statements end with a semi-colon. In contrast, an expression is a piece of code that resolves to a value, i.e. values, calculations resulting in other values, variables, and groups of variables. ...

JavaScript is one of the three core technologies used to build websites and web applications. Alongside HTML and CSS, JavaScript provides the interactive functionality commonly used throughout the web. In this lesson you will be introduced to some of the core concepts of JavaScript. To follow along, you will need a modern web browser, such as Google Chrome or equivalent with developer tools. You will also need a capable text editor. I highly recommend Microsoft Visual Studio Code. The first concept we are going to cover in this lesson is variables. Variables are spaces of memory where you can store information of a certain type, that can be retrieved later in your code. ...