IIFE (Immediately Invoked Function Expression)

const result = (() => {
  const x = 10;
  return x * 2;
})();

console.log(result);

undefined
10
20
The output will be 20. This code demonstrates an IIFE using arrow function syntax rather than the traditional function syntax. Just like with regular function expressions, an arrow function can be wrapped in parentheses to create an expression, and then immediately invoked with another set of parentheses. In this case, the arrow function sets x to 10, multiplies it by 2, and returns the result. The return value (20) is then assigned to the 'result' constant. This example shows that IIFEs aren't limited to traditional function expressions; they can be created with any function expression syntax, including arrow functions. Arrow functions in IIFEs have the additional characteristic that they don't bind their own 'this' value but inherit it from the surrounding scope.
Function object