v-bind:xx.sync

v-bind:xx.sync is a Vue.js directive that allows two-way binding between a parent component and a child component. It is used to synchronize the value of a data property between the two components.

When a value is updated in the child component, it automatically updates the value in the parent component. Similarly, when a value is updated in the parent component, it automatically updates the value in the child component.

This directive is useful when building complex components that require two-way data binding between parent and child components. It simplifies the process of passing data between components and ensures that the data stays in sync.