react state update object in array code example

Example 1: react native update state array of objects

let markers = [ ...this.state.markers ];
markers[index] = {...markers[index], key: value};
this.setState({ markers });

Example 2: how to update array in react state

this.setState(prevState => ({
  arrayvar: [...prevState.arrayvar, newelement]
}))

Example 3: update object in array state by index

this.setState(({items}) => ({
    items: [
        ...items.slice(0,1),
        {
            ...items[1],
            name: 'newName',
        },
        ...items.slice(2)
    ]
}));