How to update multiple child states in React Class Components independently? - reactjs

Question

I know how it can be done with Functional Components. But when it comes to class components, I'm having few questions to be clarified.
I've a class here,
class MyTable extends Component {
constructor(props) {
super(props);
this.state = {
page:0,
rowsPerPage:10
}
}
handleChangePage(event) {
//Here I want to update only **page** keeping **rowsPerPage** intact
}
handleChangeRowsPerPage(event) {
//Here I want to update only **rowsPerPage** keeping **page** intact
}
render() {
return(
<SomeComponent
onChangePage={this.handleChangePage}
onChangeRowsPerPage={this.handleChangeRowsPerPage}
/>
)
}
}
export default Mytable;
So here what I want to know is,
If I want to update only page inside the state object, should I have to preserve rowsPerPage and update them both as
this.setState({page:<updatedValue>, rowsPerPage:<preservedValue>);
And Vice versa
What code goes inside handleChangePage and handleChangeRowsPerPage, if we can update independent properties inside a state object.
What's the best practice when we've several such states and we want to update each one independently?

Answer 1

You can update page and rowsPerPage independently as I did bellow. You have just to call this.setState and passing and object with the key of state you want to update
class MyTable extends React.Component {
constructor(props) {
super(props);
this.state = {
page:0,
rowsPerPage:10
}
this.handleChangePage = this.handleChangePage.bind(this);
this.handleChangeRowsPerPage = this.handleChangeRowsPerPage.bind(this);
}
handleChangePage(event) {
//Here I want to update only **page** keeping **rowsPerPage** intact
this.setState({page: event.target.value});
}
handleChangeRowsPerPage(event) {
//Here I want to update only **rowsPerPage** keeping **page** intact
this.setState({rowsPerPage: event.target.value});
}
render() {
return (
<div>
<div>
Page <input type="text" value={this.state.page} onChange={this.handleChangePage} />
</div>
<div>
rowsPerPage <input type="text" value={this.state.rowsPerPage} onChange={this.handleChangeRowsPerPage} /></div>
</div>
)
}
}
ReactDOM.render(<MyTable />, document.getElementById('root'));
<script src="https://cdnjs.cloudflare.com/ajax/libs/react/16.6.3/umd/react.production.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/16.6.3/umd/react-dom.production.min.js"></script>
<div id="root"></div>