Yes, computed properties in Vue.js have caching.
Computed properties are properties that are derived from the existing data in your Vue component. They are defined as functions in the computed
option of the component. Computed properties are cached based on their dependencies, which means that their value is only recalculated when one of the dependencies changes.
Once a computed property is evaluated for the first time, its value is cached. When the dependencies of the computed property change, Vue.js checks if any of the dependencies have actually changed. If none of the dependencies have changed since the last evaluation, the computed property will return the cached value instead of recalculating it. This caching mechanism helps optimize performance by avoiding unnecessary recomputations.
Here's an example to illustrate the caching behavior of computed properties:
// Vue component new Vue({ data: { radius: 5, }, computed: { area() { console.log('Calculating area...'); return Math.PI * this.radius * this.radius; }, }, });
In this example, the area
computed property calculates the area of a circle based on the radius
data property. When the component is initialized, the computed property is evaluated and the area is calculated. If you access the area
property multiple times without changing the radius
, you will notice that the calculation is performed only once. Subsequent accesses to area
will return the cached value without re-executing the computation.
It's important to note that computed properties should be used for synchronous operations that depend on existing data. If you need to perform asynchronous or more complex operations, you should consider using a method or a watcher instead.
In summary, computed properties in Vue.js provide caching functionality to optimize performance by recalculating their value only when the dependencies change.
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