ref

react_webgame/main/index.html

@@ -32,22 +32,26 @@
 							value: '',
 							}
 						});
+						this.input.focus();
 					} else {
 						this.setState({
 							result: '땡',
 							value: '',
 						});
+						this.input.focus();
 					}
 				}
 
 				onChange = (e) => this.setState({ value: e.target.value});
 
+				onRefInput = (c) => { this.input = c; };
+
 				render() {
 					return (
 						<React.Fragment>
 								<div>{this.state.first} 곱하기 {this.state.second} 는?</div>
 								<form onSubmit={this.onSubmit}>
-										<input type="number" value={this.state.value} onChange={this.onChange}/>
+										<input ref={this.onRefInput} type="number" value={this.state.value} onChange={this.onChange}/>
 										<button>입력!</button>
 								</form>
 								<div>{this.state.result}</div>