Scop in Javascript with example

#webdev #javascript #beginners #tutorial

Scope in JavaScript refers to the visibility and accessibility of variables, functions, and objects in different parts of your code. JavaScript has three main types of scope:

Global scope
Function scope
Block scope (introduced in ES6 with let and const)

Here's an example demonstrating these scopes:

// Global scope
let globalVar = "I'm global";

function exampleFunction() {
  // Function scope
  let functionVar = "I'm function-scoped";

  if (true) {
    // Block scope
    let blockVar = "I'm block-scoped";
    var functionScopedVar = "I'm function-scoped too";

    console.log(globalVar);  // Accessible
    console.log(functionVar);  // Accessible
    console.log(blockVar);  // Accessible
    console.log(functionScopedVar);  // Accessible
  }

  console.log(globalVar);  // Accessible
  console.log(functionVar);  // Accessible
  console.log(functionScopedVar);  // Accessible
  // console.log(blockVar);  // Error: blockVar is not defined
}

exampleFunction();

console.log(globalVar);  // Accessible
// console.log(functionVar);  // Error: functionVar is not defined
// console.log(blockVar);  // Error: blockVar is not defined
// console.log(functionScopedVar);  // Error: functionScopedVar is not defined