midVue.js
What is the Composition API and why was it introduced?
Updated May 4, 2026
Short answer
It's a set of APIs that allows composing component logic using imported functions instead of options.
Deep explanation
It was introduced to solve the limitations of the Options API in large-scale projects: poor logic reuse (mixins issues) and fragmented code (logic for one feature spread across data, methods, and computed). Composition API allows grouping code by logical concern.
Real-world example
Creating a 'useMousePosition' function that can be easily shared between different components.
Common mistakes
- Mixing logic excessively so that `setup()` becomes a massive, unreadable function.
Follow-up questions
- Is Options API deprecated in Vue 3?