Summary  
This chapter explains how variable scope works in code, distinguishing global scope for variables declared outside of blocks from local scope for those inside blocks, and shows that nested scopes can access outer variables but not vice versa. It demonstrates this behavior by printing variables in different contexts to highlight valid access and errors.

General domain of usage  
JavaScript programming

A **Scope** is simply an area in the code where a variable can be accessed or used. 

Definition

There are two types of scopes:
1. **Global Scope**;
2. **Local Scope**.

If a variable is defined inside a block of code (between curly brackets `{}`), it is said to have a **local scope**. This means that it can only be accessed from **inside** that function or code block, or any **nested** blocks:



function exampleFunc() {
  let exampleVariable = 10;

  console.log(exampleVariable); // Valid

  if(10 + 10 == 20) {
    console.log(exampleVariable); // Valid
  }
}

exampleFunc();
console.log(exampleVariable); // Shows error

A variable that is defined outside of any code block is said to have a **Global Scope**, and it can be accessed from anywhere:

let exampleVariable = 10;

function exampleFunc() {
  console.log(exampleVariable); // Valid

  if(10 + 10 == 20) {
    console.log(exampleVariable); // Valid
  }
}

exampleFunc();
console.log(exampleVariable); // Valid

A variable defined in a lower (nested) scope cannot be accessed from a higher (parent) scope:

function exampleFunc() {
  if(10 + 10 == 20) {
    let exampleVariable = 10;
    console.log(exampleVariable); // Valid
  }

  console.log(exampleVariable); // Shows error
}

exampleFunc();
console.log(exampleVariable); // Shows error

Which of the following statements about variable scope is true?

Dive into the world of the most popular language for front-end development – JavaScript. JavaScript is a language built into almost every browser and can be used for a wide variety of tasks. Learn the basic functionality and prepare yourself for the challenges and more advanced programming techniques.

An introduction to JavaScript, covering the basic syntax of the language along with key terms and concepts that form the foundation for learning advanced features. The section includes hands-on tasks designed to help practice these concepts and make the content easy to remember without effort.

Scopes