Decorators enable us to extend a class or object by adding behaviors without modifying the code. Decorators wrap the class with extra functionality. They can be attached to a class, property, method, parameter, and accessor. In ECMAScript 2016, decorators are proposed to modify the behavior of a class. Decorators are prefixed with the @ symbol and a decorator name that resolves to a function called at runtime.

The following code snippet shows the authorize function, and it can be used as the @authorize decorator on any other class:

function authorize(target) { 
    // check the authorization of the use to access the "target" 
}