「React入門」React.Component継承のサンプル
書式
class クラス名 extends React.Component
使用例
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>Hello React!</title>
<script src="/react/16.4.0/umd/react.development.js"></script>
<script src="/react-dom/16.4.0/umd/react-dom.development.js"></script>
<script src="/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
<div id="cft"></div>
<script type="text/babel">
function FormattedDate(props) {
return <h2>時刻 {props.date.toLocaleTimeString()}.</h2>;
}
class Clock extends React.Component {
constructor(props) {
super(props);
this.state = {date: new Date()};
}
componentDidMount() {
this.timerID = setInterval(
() => this.tick(),
1000
);
}
componentWillUnmount() {
clearInterval(this.timerID);
}
tick() {
this.setState({
date: new Date()
});
}
render() {
return (
<div>
<h1>Hello, world!study skill in arkgame</h1>
<FormattedDate date={this.state.date} />
</div>
);
}
}
ReactDOM.render(
<Clock />,
document.getElementById('cft')
);
</script>
</body>
</html>