62 lines
2.3 KiB
Markdown
62 lines
2.3 KiB
Markdown
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---
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id: 5a24c314108439a4d403614b
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title: Create a Redux Store
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challengeType: 6
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forumTopicId: 301439
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dashedName: create-a-redux-store
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---
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# --description--
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Redux is a state management framework that can be used with a number of different web technologies, including React.
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In Redux, there is a single state object that's responsible for the entire state of your application. This means if you had a React app with ten components, and each component had its own local state, the entire state of your app would be defined by a single state object housed in the Redux `store`. This is the first important principle to understand when learning Redux: the Redux store is the single source of truth when it comes to application state.
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This also means that any time any piece of your app wants to update state, it **must** do so through the Redux store. The unidirectional data flow makes it easier to track state management in your app.
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# --instructions--
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The Redux `store` is an object which holds and manages application `state`. There is a method called `createStore()` on the Redux object, which you use to create the Redux `store`. This method takes a `reducer` function as a required argument. The `reducer` function is covered in a later challenge, and is already defined for you in the code editor. It simply takes `state` as an argument and returns `state`.
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Declare a `store` variable and assign it to the `createStore()` method, passing in the `reducer` as an argument.
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**Note:** The code in the editor uses ES6 default argument syntax to initialize this state to hold a value of `5`. If you're not familiar with default arguments, you can refer to the [ES6 section in the Curriculum](https://learn.freecodecamp.org/javascript-algorithms-and-data-structures/es6/set-default-parameters-for-your-functions) which covers this topic.
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# --hints--
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The Redux store should exist.
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```js
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assert(typeof store.getState === 'function');
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```
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The Redux store should have a value of 5 for the state.
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```js
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assert(store.getState() === 5);
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```
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# --seed--
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## --seed-contents--
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```js
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const reducer = (state = 5) => {
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return state;
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}
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// Redux methods are available from a Redux object
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// For example: Redux.createStore()
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// Define the store here:
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```
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# --solutions--
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```js
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const reducer = (state = 5) => {
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return state;
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}
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const store = Redux.createStore(reducer);
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```
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