Closures in JavaScript

Closures in JavaScript occur when a function retains access to variables from its lexical scope, even after the outer function has finished execution. This allows functions to "remember" values and maintain state.

🔹 Simple Example:

function outerFunction() {
  let counter = 0; // Local variable

  return function innerFunction() {
    counter++; // Inner function remembers 'counter'
    console.log(counter);
  };
}

const increment = outerFunction(); // Returns innerFunction
increment(); // 1
increment(); // 2
increment(); // 3

🔹 Explanation:

• outerFunction() defines a local variable (counter).
• innerFunction() modifies counter, but the outer function has already executed!
• However, innerFunction() retains access to counter due to closure behavior.
• Each call to increment() updates the retained counter, demonstrating persistent state.

Closures are useful for encapsulation, maintaining private variables, and creating efficient event handlers. 🚀