properties questions

Bcryptjs is a JavaScript library that implements the Bcrypt password hashing algorithm, which is used to securely store passwords in Node.js applications: 

Here's an overview of its key methods and properties along with examples:
const bcrypt = require('bcryptjs');
const plaintextPassword = 'mysecretpassword';

bcrypt.hash(plaintextPassword, 10, (err, hash) => {
    if (err) {
        console.error('Error while hashing:', err);
    } else {
        console.log('Hashed password:', hash);
        // Store `hash` in database for user
    }
});

The `ngModel` directive in Angular is used to create two-way data binding between form controls and component properties. It binds the value of an input element to a variable in the component and updates the variable whenever the input value changes. This two-way binding ensures that changes in the form control are reflected in the component's state and vice versa. `ngModel` is commonly used in template-driven forms to simplify the management of form inputs and maintain synchronization between the user interface and the underlying data model.

In Vue.js, a computed property is a property that is automatically recalculated based on reactive data dependencies. Computed properties are defined in the `computed` option of a Vue component and are used for performing calculations or transformations of data. Unlike methods, computed properties are cached based on their dependencies, meaning they are only recalculated when the dependent data changes. This makes computed properties efficient for scenarios where derived data needs to be computed from existing state.

Vue.js watch is a feature that allows developers to react to changes in data properties. By defining a watcher in the `watch` option of a Vue component, you can specify a function that will be called whenever the watched property changes. This is useful for performing side effects, such as making API calls or triggering additional updates, in response to changes in the component's state. Unlike computed properties, watchers do not cache their results and are invoked every time the watched data changes.

Add custom properties to `req` in middleware. For example: `app.use((req, res, next) => { req.customProperty = 'value'; next(); });` allows access to `req.customProperty` in subsequent middleware and routes.