CODEWITHSUNDEEP
react-nativestatesetstate
pnizzle
pnizzle

Reputation: 6431

React Native: when updating one item in state, do I need `...this.state`

In react native, when I wish to update the value of one item in the state dictionary, this is how I do it:

this.setState({
    showFullImage: true,
})

but some developers in my team add ...this.state like this:

this.setState({
    ...this.state,
    showFullImage: true,
})

To me this is wrong since it will update everything reliant on state. Including anything that may not need updating. My approach (first one) has been working all along, and does not remove all other values from state... Am I wrong in this?

Upvotes: 0

Views: 124

Answers (2)

Kishan Mundha
Kishan Mundha

Reputation: 3141

setState method update state value for provided key. It only update selected keys. So if you want to update single property of state you can directly update.

If you want to update single property of child level than you need ... For example.

this.state = {
    showImage: true,
    user: {
        name: 'test',
        age: 10
    }
}

updateName(name) {
    const { user } = this.state
    this.setState({
        user: {
            ...user,
            name
        }
    })
}

toggleImage() {
    const { showImage } = this.state
    this.setState({
        showImage: !showImage
    })
}

Upvotes: 0

dentemm
dentemm

Reputation: 6379

You are right, there is no need to spread out the parts of the state you are not updating. Only update what needs to be updated.

Upvotes: 1

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