react allow only numbers in input
class App extends React.Component{
constructor(){
super();
this.state = {value: ''};
this.onChange = this.onChange.bind(this)
}
onChange(e){
const re = /^[0-9\b]+$/;
if (e.target.value === '' || re.test(e.target.value)) {
this.setState({value: e.target.value})
}
}
render(){
return <input value={this.state.value} onChange={this.onChange}/>
}
}
ReactDOM.render(<App/>,document.getElementById('app'))