====== !! Double not operator ====== The double NOT operator (!!) in JavaScript is a bit of a trick that converts any value to its corresponding boolean value.\\ How it works: - The first **!** negates the value, converting it to its opposite boolean value. If the original value is truthy, this results in **false**, and if the original value is falsy, this results in **true**. - The second **!** negates it again, so you're back to the original truthiness of the value, but now as a boolean **true** or **false** instead of the original value. Examples: !!true; // true !!false; // false !!null; // false !!undefined; // false !!0; // false !!1; // true !!'hello'; // true !!''; // false This trick is often used when you want to ensure that a value is a boolean, and it behaves in the same way as if you had used the **Boolean constructor**. It's a more concise way to force a value into a boolean context, and it's used quite frequently in JavaScript code.