Javascript

This article will explain what absolute values are, how they are used, and how the JavaScript Math.abs() function can be used to calculate the absolute value of a number. What is the ‘Absolute Value’ of a Number? The absolute value of a number is that number’s value – without any regard to its sign. A numbers sign determines whether it is positive or negative – it’s the – symbol before a negative number. So, the absolute value of a number is never negative. Consider the absolute value of a number that numbers distance from 0. The absolute value of … Read more

This short article shows you how to capitalize the first letter in a string or all of the words in a string (title case) in the javascript programming language. Capitalizing the first letter in a string is useful if you’re capitalizing a single word or a whole sentence which you wish to display in a grammatically correct manner. Converting a string to title case – that’s where every word is capitalized in a string with multiple words – is useful for formatting text for use in an article … Read more

This quick tutorial will show you how to check whether an array is empty in the JavaScript programming language. What is an Array? An array is a type of variable that holds a collection of zero or more values. In JavaScript, arrays are ordered – each value in the array has a position (called the index) in the array, which is used to access it. Indexes start counting at 0, so the first value in an array is at index 0. Declaring an Array in JavaScript The quickest way to … Read more

This quick article will show you the right way to reset/clear/empty an array in the JavaScript programming language. The Right Way to Reset/Clear/Empty an Array – Set the length to 0 This is the best way to reset/clear/empty an array in JavaScript. It is unambiguous and will affect both the variable containing the array and any variables referencing the array. var myArray = [1, 2, 3, 4]; myArray.length = 0; Above, an array is declared and then emptied by setting the array’s length property to 0. The Wrong Way – Re-declare the … Read more

This article will show you how to read a JSON file into JavaScript as a JSON object – both local and remote files. What is JSON? JSON (JavaScript Object Notation) is a file format that stores objects, and arrays of objects, as human-readable text. It’s become the most popular method of storing and transmitting structured data on the internet. Thousands of APIs (used for mapping, communication, authentication, and many other purposes) use it as the format for submitting and receiving data. Desktop applications also use it to … Read more

This article will show you how to write to files from JavaScript – both from the web browser and Node.js environments. With examples on how to write, append, update, delete and rename files. JavaScript code is usually run from one of two environments – within a web browser when viewing a web page or in a Node.js environment which allows JavaScript to be executed outside of a web browser – commonly used for building back-end services and web apps. Write to a File From the Browser … Read more

This article will explain floating-point numbers and how to convert values to floating-point numbers using parseFloat() in JavaScript. Looking to convert to an integer value instead – use parseInt()! What is a Floating Point Number? In programming, a floating-point number (commonly just called a float) is a number with any number of characters before or after a decimal point. A floating-point number might look something like this: 14.392 A floating-point number or float is also a type of variable. A variable’s type determines what kind of values it can store and what can be done with the variable … Read more

Here are some easy-to-understand methods for converting strings to date objects in the JavaScript Programming language. Looking to compare dates in JavaScript? Find out how here. The Hard Way – Using Vanilla JavaScript JavaScript contains built-in functions for parsing a date from a string – but it’s severely limited. So here it is in action: var myString = ’01 Jan 1970 00:00:00 GMT’; var myDate = new Date(Date.parse(myString)); What’s happening here? A string is defined containing a date. A new Date object is then defined using the … Read more

A queue is a commonly used data structure in programming. Here’s how to implement and use a queue in JavaScript. JavaScript doesn’t include a data structure specifically called a queue – but that doesn’t mean the functionality isn’t there. JavaScript arrays can be used in the same way – it’s just the terminology that’s a bit different. Rather than duplicating array functionality for queues, queue functionality exists in the array functions of JavaScript. What is a Queue Data Structure? A queue is a sequence of items in a specific order. Items can be enqueued (added … Read more

There are several ways to declare an array in JavaScript. This article will show you which is the best. What is an Array? An array is a type of variable that holds an ordered list of values. Each value has a position in the array, called the index. The index can be used to access each value in the array. Indexes are integer values, which start counting from 0 (zero) for the first item in the array. The Literal Constructor – Declaring an Array using Square Brackets (The Best … Read more