react how to update state code example
Example 1: state with react functions
import React, { useState } from 'react';
function Example() {
const [count, setCount] = useState(0);
return (
<div>
<p>You clicked {count} times</p>
<button onClick={() => setCount(count + 1)}>
Click me
</button>
</div>
);
}
Example 2: how to update react state array
const [myArray, setMyArray] = useState([1,2,3])
setMyArray([...myArray, 4]);
Example 3: how to update array in react state
this.setState(prevState => ({
arrayvar: [...prevState.arrayvar, newelement]
}))
Example 4: state with react functions
class Example extends React.Component {
constructor(props) {
super(props);
this.state = {
count: 0
};
}
render() {
return (
<div>
<p>You clicked {this.state.count} times</p>
<button onClick={() => this.setState({ count: this.state.count + 1 })}>
Click me
</button>
</div>
);
}
}
Example 5: setstate react js
constructor(props) {
super(props);
this.state = {
isActive: true,
};
}
checkStatus = () => {
this.setState({
'isActive' : !this.state.isActive,
});
}
Example 6: update state in react
You have to use setState() for updating state in React
{
hasBeenClicked: false,
currentTheme: 'blue',
}
setState({
hasBeenClicked: true
});