Can export default in Vue export multiple

Vue's export default can only export a single entity (object, function, or class) and does not allow exporting multiple things. This has to do with the idea of ​​modularity, with the aim of simplifying the import process and keeping the code clear. If you need to export multiple parts, you should use the export keyword to export them separately, and use the corresponding name when importing. Although an object contains multiple properties and methods internally, it still counts as a single entity, so it can also be exported using export default. Choosing which export method to use should be traded down based on specific requirements and component complexity to keep the code readable and simplistic.

export default in Vue: Do you really understand it?

Many beginners will ask: Can Vue's export default export multiple things? The answer is: No. But behind this problem is a deeper understanding of modularity and Vue component export mechanism. This article will give you an in-depth analysis.

Let’s talk about the conclusion first: export default can only export one thing. This "a thing" can be an object, a function, or even a class, but it can only be a single named exit. If you try to export multiple things, the compiler will directly report an error.

Why is it designed like this? This is closely related to modular thinking. The purpose of export default is to provide a default export to simplify the import process. Imagine if multiple exports are allowed, you need to specify the name of each export when importing, which increases the complexity and redundancy of your code. Keep a single export to make the code clearer and easier to maintain.

Let's look at an example, an example of error:

 <code class="javascript">// 错误示范：试图导出多个export default { data() { return { message: 'Hello' }; }, methods: { greet() { console.log(this.message); } }, components: { // ... } };</code>

This code tries to export data , methods and components at the same time, which is wrong. The compiler throws an error.

So, what is the right way to do it? We need to use the export keyword to export different parts:

 <code class="javascript">// 正确做法：分别导出const data = () => ({ message: 'Hello' }); const methods = { greet() { console.log(this.message); } }; const components = { // ... }; export { data, methods, components }; //或者，更简洁的写法： export { data: () => ({ message: 'Hello' }), methods: { greet() { console.log(this.message); } }, components: {/*...*/} };</code>

In this way, we can import these parts separately. When importing, you need to use the corresponding name:

 <code class="javascript">import { data, methods, components } from './myComponent'; // 使用导入的内容const MyComponent = { data, methods, components, };</code>

You may ask: What about the object? An object can contain multiple properties and methods. Does this count as multiple exports? Yes, but it is still a single entity. The export default exported object, its internal properties and methods can still be accessed through dots after import. This is different from deriveing ​​each property and method separately. The former maintains the integrity of the object, while the latter breaks it down into separate parts.

Which method to choose depends on your specific needs. If your component structure is relatively simple, it may be more convenient to export an object using export default . But if your components are very complex or need to reuse parts, it would be better to export the individual parts separately. This needs to be weighed based on actual conditions.

Finally, one experience: Keeping the code simplicity and readability is crucial. Don't write incomprehensible code in order to pursue so-called "skills". The best practice is to choose the clearest and easiest way to maintain. Remember, code is written for people to see, followed by machines.

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