Web Developer's Reference Guide

Scoped variables and constants

When we declare a variable, then it has a local scope and a global scope. We can define a variable anywhere in our script. When we declare a variable in JavaScript, we can assign a value to it at the time of declaration or later. Here is an example:

_xyz123; // variable declared without assigning a value to it
varabc = "Star"; //variable declared while assigning a value to it

In JavaScript, a variable is defined by a dollar sign the same as in query. In JavaScript, we create variables dynamically using the var keyword. Every variable has a name and a value associated with it. These values can be of any type, such as number, array, string, and so on. A variable name could be a combination of characters and numbers. ...