Vue3 computed传参

### Vue3 Computed Properties Passing Parameters

In Vue.js, computed properties are typically used without arguments because they rely on reactive dependencies that automatically trigger updates when those dependencies change. However, there exists a pattern where one can simulate passing parameters to computed properties by using nested functions or methods inside the computed property definition.

For scenarios requiring parameterized logic similar to what might be desired with computed properties, consider employing methods instead since these naturally accept parameters[^1]. Yet, if maintaining reactivity while emulating argument-passing behavior remains essential, an alternative approach involves leveraging closures within computed definitions as shown below:

new Vue({
  el: '#app',
  data() {
    return {
      items: [
        { id: 1, name: 'Apple' },
        { id: 2, name: 'Banana' }
      ]
    };
  },
  computed: {
    getItemById() {
      const vm = this;
      return function(id) {
        return vm.items.find(item => item.id === id);
      };
    }
  }
});

This code snippet demonstrates how to create a pseudo-parameterized computed property through returning a closure from the computed property which then accepts parameters during invocation elsewhere in your component's template or script section.

When it comes specifically to integrating such functionality into components like `v-model` usage demonstrated earlier, remember that computed setters/getters operate based on internal state changes rather than external inputs directly passed at call time. Therefore, adapting this concept would involve adjusting reactive sources accordingly so any dependent computations reflect updated values appropriately.

--related questions--

1. How does Vue handle reactivity internally?
2. What alternatives exist for achieving dynamic computation besides computed properties?
3. Can watchers achieve effects similar to parameterized computed properties?
4. In what situations should developers prefer methods over computed properties?
5. Is it possible to optimize performance when frequently recalculating complex derived states?