Renders a component with collapsible content.

  • Use the React.setState() hook to create the isCollapsed state variable with an initial value of props.collapsed.
  • Use an object, style, to hold the styles for individual components and their states.
  • Use a <div> to wrap both the <button> that alters the component’s isCollapsed state and the content of the component, passed down via props.children.
  • Determine the appearance of the content, based on isCollapsed and apply the appropriate CSS rules from the style object.
  • Finally, update the value of the aria-expanded attribute based on isCollapsed to make the component accessible.


function Collapse(props) {
  const [isCollapsed, setIsCollapsed] = React.useState(props.collapsed);

  const style = {
    collapsed: {
      display: 'none'
    expanded: {
      display: 'block'
    buttonStyle: {
      display: 'block',
      width: '100%'

  return (
      <button style={style.buttonStyle} onClick={() => setIsCollapsed(!isCollapsed)}>
        {isCollapsed ? 'Show' : 'Hide'} content
        style={isCollapsed ? style.collapsed : style.expanded}


    <h1>This is a collapse</h1>
    <p>Hello world!</p>