Book Image

JavaScript for .NET Developers

By : Ovais Mehboob Ahmed Khan
Book Image

JavaScript for .NET Developers

By: Ovais Mehboob Ahmed Khan

Overview of this book

If you want to improve responsiveness or the UX in your ASP.NET applications, JavaScript can be a life saver. In an age where server-side operations have shifted to the client, being able to handle JavaScript with confidence and fluency is vital for ASP.NET developers. There’s no point trying to fight it, so start learning with this book. Make sure your projects exceed user expectations. Begin by getting stuck into the basics of JavaScript, and explore the language in the context of ASP.NET Core. You’ll then find out how to put the principles into practice, as you learn how to develop a basic ASP.NET application using Angular 2 and TypeScript. You’ll also develop essential skills required to develop responsive apps, with a little help from AJAX, ensuring that you’re building projects that can be easily accessed across different devices. With guidance on Node.js and some neat techniques to test and debug a range of JavaScript libraries in Visual Studio, you’ll soon be well on your way to combining JavaScript with ASP.NET in a way that’s capable of meeting the challenges of modern web development head-on.
Table of Contents (17 chapters)
JavaScript for .NET Developers
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Variables – scope and hoisting


We already know how variables are declared in JavaScript using the var keyword. Any variable that is declared using the var keyword is termed a hoisted variable, and the term hoisting is the JavaScript default behavior of moving declarations to the top. When JavaScript is compiled by the JavaScript engine, all the variables that are declared using the var keyword are placed at the top within its scope. This means that if the variable is declared within a function block, it will be placed at the top of the function; otherwise, if it's declared outside any function and at the root of the script, it will become globally available. Let's have a look at this example to clarify our understanding.

Let's suppose the following code is the simple program that returns the GMT of the country name passed in the function's parameter:

function getCountryGMT(countryName) {
  if (countryName == "Pakistan") {
    var gmt = "+5.00";
  }
  else if (country == "Dubai") {
    var...