javascript - React change state dynamicly for multiple components -

i have issue react component. have this

class sidebaritem extends react.component{ constructor(props) {     super(props)     this.state = { isactive: false } } handleclick() {     var active = !this.state.isactive;     this.setstate({ isactive: active }); } render() {     var classname = 'item';     if(this.state.isactive){classname = 'active item'} else {classname = 'item'};     return (         <link classname={classname} to={this.props.href} onclick={this.handleclick.bind(this)}>             {this.props.label}         </link>     ); } }   export class sidebar extends react.component { constructor(props) {     super(props) } render() {     var elements = this.props.defaults.elements.map(function (i) {         return (             <sidebaritem label={i.label} href={i.href} key={i.label} />         );     });     return (             <div classname={this.props.defaults.class}>                 {elements}             </div>     ); } }; 

my aim change classname active element of menu. can't understand, how must translate elements clear active state , active 1 clicked element?

i think looking this

class menu extends react.component {   constructor(){     super()     this.state = {       items: ['hello', 'world', 'it', 'is', 'me'],       active: 0     }   }   click(index){     this.setstate({active: index})   }   render(){     const list = this.state.items.map((item,index) => {       return <item key={index}          classname={this.state.active === index ? 'active' : ''}          text={item}         click={this.click.bind(this, index)}       />     })     return <ul>         {list}     </ul>   } }  class item extends react.component {     constructor(){     super();   }   render(){     return <li onclick={this.props.click}               classname={this.props.classname}>              {this.props.text}            </li>           } }   react.render(<menu />, document.getelementbyid('container')); 

hope fiddle