> For the complete documentation index, see [llms.txt](https://it2805.gitbook.io/curriculum/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://it2805.gitbook.io/curriculum/javascript-continued/scope.md).

# Scope

The scope determines the accessibility to variables and functions. If something is "outside of scope" it means we can not access it.

![](/files/-MDnCeG_-6ynFr0QXKmf)

## Global

The global scope is the scope that is accessible from anywhere. Anything that is defined outside of a function is a part of the global scope.

Consider this very simple program. It only contains a single variable called `planet`. The variable is a part of the global scope because it is defined outside any function.

```
var planet = 'earth';
```

## Local

However, if the variable had been defined inside a function instead it would no longer belong to the global scope.

```
function universe() {
    var planet = 'earth';
}
```

`planet` is no longer in the global scope, but instead constrained to the scope of the `universe` function.

```
function universe() {
    var planet = 'earth';
}

console.log(planet);
```

In other words, it is inaccessible from the global scope. Which in turn means that the code above would throw a `ReferenceError` stating that `planet is not defined`.

## Lexical

Another useful (but perhaps counterintuitive) scope is the lexical one. It provides a function within another function access to the scope of the outer function.

```
function universe() {
    var planet = 'earth';

    function milkyWay() {
        console.log\(planet\);
    }
}
```

Calling the `milkyWay` function would log out `earth` in the case above.