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Lära Challenge | Lifecycle Methods
React Tutorial
course content

Kursinnehåll

React Tutorial

React Tutorial

1. Getting Started
2. Lifecycle Methods
3. Functional Components and Hooks
4. Advanced Topics

book
Challenge

Task

GIven a React component that displays a list of items. The component should have two lifecycle methods: componentDidMount and componentDidUpdate.

In the componentDidMount method, you should fetch a list of items from a server and update the component's state with the new list of items. In the componentDidUpdate method, you should check if a new item has been added to the list of items. If a new item has been added, you should fetch the updated list of items from the server and update the component's state with the new list.

Your tasks are as follows:

  • Initialize the empty array of items in the state variable.

  • Implement a componentDidMount function calling the fetchItems method.

  • Write two conditions, one that checks whether the item is in the array using includes and the other using the find method.

  • Set the state variable items in the fetchData method.

  • Add a list item looping over the items.

Hints:

  • ComponentDidMount has no params, just calls the method this.fetchItems.

  • Match the newItem in includes and for find check whether item.name matches or not.

  • Remember to add the key to the list item as item.id along with the name.

Solution

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 2. Kapitel 8

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course content

Kursinnehåll

React Tutorial

React Tutorial

1. Getting Started
2. Lifecycle Methods
3. Functional Components and Hooks
4. Advanced Topics

book
Challenge

Task

GIven a React component that displays a list of items. The component should have two lifecycle methods: componentDidMount and componentDidUpdate.

In the componentDidMount method, you should fetch a list of items from a server and update the component's state with the new list of items. In the componentDidUpdate method, you should check if a new item has been added to the list of items. If a new item has been added, you should fetch the updated list of items from the server and update the component's state with the new list.

Your tasks are as follows:

  • Initialize the empty array of items in the state variable.

  • Implement a componentDidMount function calling the fetchItems method.

  • Write two conditions, one that checks whether the item is in the array using includes and the other using the find method.

  • Set the state variable items in the fetchData method.

  • Add a list item looping over the items.

Hints:

  • ComponentDidMount has no params, just calls the method this.fetchItems.

  • Match the newItem in includes and for find check whether item.name matches or not.

  • Remember to add the key to the list item as item.id along with the name.

Solution

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 2. Kapitel 8
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