Function (local) variables are deleted when the function is completed. In a web browser, global variables are deleted when you close the browser window (or tab).

Declaring JavaScript Variables Creating a variable in JavaScript is called declaring a variable. You declare a JavaScript variable with the let keyword or the const keyword.

All variables used in a function should be declared as local variables. Local variables must be declared with the var, the let, or the const keyword, otherwise they will become global variables.

What are Environment Variables? Environment variables are dynamic named values that can affect how running processes behave on a computer. They are part of the environment in which a process runs …

What is a Template Reference Variable? Gives a local name (e.g., #box) to an element or directive instance. Lets you read values or call methods directly in the template. Scoped to the template where …

Closures make it possible for a function to have "private" variables. A closure is created when a function remembers the variables from its outer scope, even after the outer function has finished executing.

Unless you were in strict mode, then you would get an error if your variables were undefined. Now, with ES6, there are three ways of defining your variables: var, let, and const.

Well organized and easy to understand Web building tutorials with lots of examples of how to use HTML, CSS, JavaScript, SQL, Python, PHP, Bootstrap, Java, XML and more.

Declare many variables in one statement. Start the statement with var and separate the variables by comma:

What is HTML Web Storage? With web storage, applications can store data locally within the user's browser. Before HTML5, application data had to be stored in cookies, included in every server …