Scope

Scope refers to the variables you have access to at various levels in your application. The {} are there to help you define scope in your files. Let's look at two important types of scope: local and global.

File Location

We will be working in the following file:

    javascript-library
        └── 1-Fundamentals
            └── 4-Functions
                04-scope.js <----You will be working in this file.

Global JavaScript Variables

A variable declared outside a function, becomes GLOBAL. All scripts and functions on a web page can access it.

var carName = " Volvo";

// code here can use carName

function myFunction() {
    // code inside this function can use the variable  
    carName = "Lamborghini";
}

Local Scope

Variables defined inside a function cannot be accessed from anywhere outside the function. Take the following example:

function myFunction() {
    var carName = "Volvo";
    // code here can use carName
}
console.log(carName)//Throws an error because the carName variable is not accessible here

Again, the carName variable is defined and accessible only in the scope of the function.

More on scope

There is a lot more to know on scope, and we will discuss it as we move forward.