javascript - React.js How do I get the id in props with the getElementById method? -

start learn react.js , encounter following problem: enter image description here

i want div element using getelementbyid doesn't work , console alerts can not read property 'props' of null. how can div element? has troubled me several hours. thanks.

the whole idea react don't access dom, work virtual dom.

to achieve trying accomplish (which little unclear since code incomplete), you'll want use stateful component stores user input on this.state. check out this page on react forms.

you'll want this, tracking user input storing on component:

class nameform extends react.component {   constructor(props) {     super(props);     this.state = {value: ''};      this.handlechange = this.handlechange.bind(this);     this.handlesubmit = this.handlesubmit.bind(this);   }    handlechange(event) {     this.setstate({value: event.target.value});   }    handlesubmit(event) {     alert('a name submitted: ' + this.state.value);     event.preventdefault();   }    render() {     return (       <form onsubmit={this.handlesubmit}>         <label>           name:           <input type="text" value={this.state.value} onchange={this.handlechange} />         </label>         <input type="submit" value="submit" />       </form>     );   } }