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'))
