Search Results for: javascript string

What is null in JavaScript, and how can you check if a value is equal to null? Read on to find out. What is Null? Null is a term with a special meaning in computing and computer programming. Null is not 0 (zero). Null means that something has no value. Zero is a value (a number). An empty string has a value (though sometimes called a null string, they aren’t null). A variable with a value of null is considered to be empty. It is not undefined – it has been defined … Read more

This article will show you how to create and consume Enums in JavaScript. Unfortunately, javaScript does not include native support for Enums, but you can add comparable functionality yourself. Note that TypeScript, a language that builds on JavaScript, does include support for Enums natively. So we’re only looking at plain JavaScript here – not TypeScript. What is an Enum? An Enum (Enumerated Type) is a data structure containing multiple values. Each value is assigned to an identifier – and can be accessed by that identifier. Enums contain pre-defined constants … Read more

This short article will explain what ‘undefined’ means in JavaScript – as both a type and a variable value. Creating a Variable with an undefined value To create a variable with an undefined value, it simply needs to be declared with no assigned value, for example: var myVariable; console.log(myVariable); If the above code is executed, undefined is logged as the value of myVariable as no value was assigned. undefined is a Type of Variable undefined is one of the primitive variable types in JavaScript. A variable type describes what a variable can be used for (for … Read more

This short tutorial aims to get you started creating and using JavaScript modules and provides some simple examples. What is ES6? JavaScript’s official name is actually ECMAScript, and version 6 introduced module functionality to create and consume modules, so you might see JavaScript Modules referred to as ES6 or ES2015 Modules. What is a JavaScript Module? As you get more adventurous with your JavaScript programming projects and your code becomes more complex, it might start to become harder to manage. One way of mitigating this is splitting … Read more

This article will explain JavaScript variable types and how to find the type of a variable using the typeof operator. The typeof operator is quite similar to the instanceof operator – but they do not function the same way.  instanceof returns TRUE or FALSE when checking if a variable is of a certain type, whereas typeof returns the name of the type. What are Types? The type of a variable determines what it can or can’t do. It determines what value the variable may take and … Read more

This easy tutorial will show you how to use the JavaScript string trim() method and give some example usage. The trim()* method is available to any string type variable in JavaScript. It removes any white space (spaces, tabs, newlines) found at the beginning and the end of the string. Why is this useful? Sometimes you wind up with a bunch of un-needed white space padding your strings – often from the end-user hammering the space key when a space isn’t required. Unnecessary white space can also occur after splitting … Read more

We’ve covered arrays in JavaScript pretty extensively on LinuxScrew. This article will show you how to use the filter method – with easy-to-follow examples. JavaScript Arrays Arrays are a type of variable that holds a list of other values or variables. They’re one of the fundamentals of computer programming. These lists contain items at positions (called indexes). These items can be anything – numbers, strings, complex objects – whatever you want to store. Arrays are super useful. You might use them to store the rows in a … Read more

This article will show you how to compare arrays in JavaScript and provides some ready-to-use functions to do so. We’ve already covered a bit on how to use arrays in JavaScript: Looping over Array using JavaScript forEach(), With Examples Array slice() Method in JavaScript, with Examples() Check Array Contains a Value in JavaScript, with Examples Removing an Element From an Array in JavaScript, with Examples What is an Array? An array is a type of JavaScript variable that can hold other variables, or references to … Read more

This article will explain what the JavaScript instanceof operator does and how it can be used. Examples provided. What does instanceof do? The instanceof operator returns TRUE or FALSE depending on whether a given value or variable is of a certain type or class – it checks whether a value is an instance of a given object class or type. The purpose of instanceof may seem confusing – you already have typeof, so what do you need instanceof for? typeof will simply return a string containing the name of the type or class of the variable. In contrast, instanceof will return a … Read more