CODEWITHSUNDEEP
reactjsreact-native
Daniel Corona
Daniel Corona

Reputation: 1222

Update state array in React Native

I'm trying to fill an empty state array with the elements of a Firebase database

retrieveCategories = async () => {
 const { categories } = this.state;
 const { eventTypes } = constants;
 let count = eventTypes;

 const snapshot = await firebase.database().ref('/categories').once('value');

 while (count !== -1) {
   const cat = snapshot.val()[count];
   this.setState(prevState => ({ categories: [...prevState.categories, cat] }));
   count -= 1;
 }

 console.log(categories);
}

The problem is that no matter what I do, the array does not update itself, proven when the console.log(categories); only throws a [].

What can I do to solve this issue?

Upvotes: 0

Views: 35

Answers (1)

Ali Hayder
Ali Hayder

Reputation: 325

You can do it like this

let {categories} = this.state
categories.push(cat)
this.setState({categories})

Also console.log(this.state.categories) because the state is updated after this.setState.

Upvotes: 1

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