and detailed explanation of use

()effect

The official documentation mentions that () can be used to register global plug-ins. After using(), the plug-in can be used anywhere in the project.

So when to use()?

In fact, the official documentation also gives a very detailed answer, which is to use () when a plug-in object or function has an install method.

When calling(), the plug-in's install method is called, so that it can be used globally.

Vue usage scenarios

Use of official plug-ins such as VueRouter

A series of plug-ins for assisting development are provided in the vue official community, many of which have install methods, such as ElementUI and VueRouter, which we use () to introduce.

import Vue from 'vue'
import VueRouter from 'vue-router';
import Element from 'element-ui'

(VueRouter);
(Element);

2. Customize the plug-in and provide the install method

In addition to using official plugins, we can also customize some plugins containing the install method.

import Icon from '../components/icon/index'
const IconConponents = {
  // install is the default method.  When the outside world uses the component, it will call its install method and pass a parameter of the Vue class at the same time.  install: function (Vue) {
    ('Icon', Icon)
  }
}
// Exportexport default IconConponents

Register the plugin in

import Icon from './global'
(Icon)

effect

It is a way to register global variables, and the variables used can be accessed globally. The most typical example is axios.

import axios from 'axios';
.$http = axios;

After registering axios, you can use it in the project location. How to use it:

Callthis.$httpMake an access.

In fact, we should also note that the registered global variables must be used beforeAdd $ symbol, this is a norm, mainly to prevent naming conflicts.

Difference between () and

Having said that, let’s take a closer look at the difference between these two methods.

It's actually very obvious, () is used for registrationHave install methodAfter registering the variable, the install function willAutomatic call, enables the specific variables of install to be used globally, including global variables, global tags, etc.

It is a method to register global variables. The registered global variable starts with $ and calls this method to call.

Summarize

The above is personal experience. I hope you can give you a reference and I hope you can support me more.