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React Design Patterns and Best Practices

You're reading from   React Design Patterns and Best Practices Build easy to scale modular applications using the most powerful components and design patterns

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Product type Paperback
Published in Jan 2017
Publisher Packt
ISBN-13 9781786464538
Length 318 pages
Edition 1st Edition
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Author (1):
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Michele Bertoli Michele Bertoli
Author Profile Icon Michele Bertoli
Michele Bertoli
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Table of Contents (13) Chapters Close

Preface 1. Everything You Should Know About React FREE CHAPTER 2. Clean Up Your Code 3. Create Truly Reusable Components 4. Compose All the Things 5. Proper Data Fetching 6. Write Code for the Browser 7. Make Your Components Look Beautiful 8. Server-Side Rendering for Fun and Profit 9. Improve the Performance of Your Applications 10. About Testing and Debugging 11. Anti-Patterns to Be Avoided 12. Next Steps

Using indexes as a key

In Chapter 9, Improve the Performance of Your Applications, talking about performance and the reconciler, we have seen how we can help React figure out the shortest path to update the DOM by using the key prop.

The key prop uniquely identifies an element in the DOM and React uses it to check if the element is new or if it has to be updated when the component props or state change.

Using keys is always a good idea and, if you don't do it, React gives a warning in the console (in development mode). However, it is not simply a matter of using a key; sometimes the value that we decide to use as a key can make the difference. In fact, using the wrong key can give us unexpected behaviors in some instances. In this section, we will see one of those instances.

Let's, again, create a List component:

class List extends React.PureComponent 

In the constructor, the items are initialized and the handlers bound to the component:

constructor(props) { 
  super(props) 
 
  this...
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