Understanding Vue.js Mixins: Basics, Usage, and Differences from Vuex and Components

Mixins are a flexible mechanism for distributing reusable functionality across Vue components. A mixin object can contain any component options, and when a component includes a mixin, all of the mixin's options are merged into the component's own options.

How to use

First, define a mixin object:

Then, add the mixin to a component's mixins array:

Characteristics

1. Methods and data defined in a mixin are not shared between components; each component receives its own copy. The example shows a numeric property num that is incremented in component 1 while remaining unchanged in component 2.

2. Options that are objects (e.g., methods , components ) are merged; if a component defines the same key, the component's definition overrides the mixin's.

3. Options that are functions (e.g., lifecycle hooks like created , mounted ) are merged and both are called, with the mixin's hook executing before the component's.

Difference from Vuex

Vuex provides a global state store; a change to a variable in one component is reflected in all other components. In contrast, mixins define shared variables that are independent per component, so modifications in one component do not affect others.

Difference from regular components

A regular component is imported and used as a child, communicating via props , and remains largely independent. A mixin, however, is merged into the parent component's options, effectively extending the component with additional data and methods.