Mastering JavaScript Variables: let, const, and var Explained in 1 Minute

JavaScript offers three ways to declare variables: var, let, and const. While they all serve the same purpose, their behavior differs significantly. Here’s a quick guide:

1. var

• Scope: Function-scoped, meaning it’s only accessible within the function where it’s declared.
• Hoisting: Gets hoisted to the top of its scope but initialized as undefined.
• Use Case: Mostly used in older codebases. Avoid using it in modern JavaScript.

function example() {
  var x = 10;
  if (true) {
    var x = 20; // Same variable redeclared
    console.log(x); // 20
  }
  console.log(x); // 20
}

2. let

• Scope: Block-scoped, meaning it’s accessible only within the {} block it’s defined in.
• Hoisting: Also hoisted, but not initialized (accessing it before declaration causes an error).
• Use Case: Ideal for variables that may need to be reassigned.

let y = 10;
if (true) {
  let y = 20; // New variable in block scope
  console.log(y); // 20
}
console.log(y); // 10

3. const

• Scope: Block-scoped, like let.
• Hoisting: Same as, but must be…