update state in function react code example

Example 1: how to update array in react state

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

Example 2: reading state react

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 3: reading state react

<p>You clicked {count} times</p>

Example 4: reactjs update state example

{
  hasBeenClicked: false,
  currentTheme: 'bluesss',
}s

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Javascript Example

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