That's what undefined means; regardless of its semantics in English, its Javascript meaning is that the variable hasn't been declared or populated yet, and so while the concept of "a variable called foo" is valid, there exists no variable with that name holding a real value. Sha...
JavaScript is a high-level, interpreted programming language that is primarily known for its role in enhancing web pages to provide a more dynamic and interactive user experience. Developed initially by Netscape, JavaScript has evolved to become one of the core technologies of theWorld Wide Web, al...
It adds it to the window because window is the object that called the function when you execute it like that, and this in a function is the object that called the function. In JavaScript at least. Now, call it like this with new: var bar = new Foo(); When you add new to a fu...
Modernizr is a JavaScript library that greatly eases HTML5 development; I’ll discuss it in depth in a future article. The takeaway here is that even though HTML5 is just emerging in our browsers, official tool support is quickly being added, and Microsoft is even adding support for ...
In simple terms, Vue is a JavaScript library that allows you to build user interfaces using different components. Each component can be reused in different parts of your application, making it easy to create complex and scalable user interfaces. Vue also uses a reactive data model, which means...
What Is Node.js and Why You Should Use It Node.js is a highly-scalable event-driven JavaScript environment. In this article, learn more about Node.js, its architecture, how to use it, and m… Reading time 14 min read Updated date ...
scripts are processed on the server, client-side scripting -- particularly JavaScript -- is still used extensively in web development. For this reason, websites often require users to configure their browsers to permit client-side scripts to run. Otherwise, certain webpage features might not work...
Checking for null in JavaScript: 12345lettext =null;if(text ===null) {console.log("This text is null"); } People often mix upundefinedwithnullin JavaScript, but a variable is said to be undefined when it does not exist and is not defined to have any value, while a variable is said...
This is a concept in the interface of ts. The interface of ts is "duck typing" or "structural subtyping", and type checking mainly focuses on the shape that values have. So let's get acquainted with the interface first, and then elicit the explanation of ?. ...
If this is so then it defines 'factory' and passes jQuery to it as a dependency. Otherwise it sets up the dependencies that the code needs by attaching them to the root object. As for what 'factory' is: it is not defined by the Javascript framework, it will be a function in the sa...