구구단
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
<title>Document</title>
<script crossorigin src="https://unpkg.com/react@17/umd/react.development.js"></script>
<script crossorigin src="https://unpkg.com/react-dom@17/umd/react-dom.development.js"></script>
<script src="https://unpkg.com/@babel/standalone/babel.min.js"></script>
</head>
<body>
<div id="root"></div>
<script type="text/babel">
class GuguList extends React.Component{
renderList(n){
let g = parseInt(n)
let arr = Array(9).fill(null)
return(
arr.map((v,k)=>{
return<li key={k}>{g}*{k+1}={g*(k+1)}</li>
})
)
console.log('renderlist')
}
render(){
return(
<>
<li>{this.props.gugu}단 입니다.</li>
{this.renderList(this.props.gugu)}
</>
)
console.log('render1')
}
}
class GuguForm extends React.Component{
render(){
return(
<>
<li>
<h2>몇단을 구하시겠습니까?</h2>
<form onSubmit={this.props.onSubmit}>
<input type="number" name="gugu" placeholder="숫자를 입력해주세요"/>
<input type="submit" value="조회"/>
</form>
</li>
{this.props.isSubmit?<GuguList gugu={this.props.gugu}/>:'몇단을 구하시나요?'}
</>
)
console.log('formrenderlist')
}
}
class App extends React.Component{
constructor(props){
super(props)
this.state = {
isSubmit:false,
gugu:0
}
}
onSubmit = (e) => {
e.preventDefault()
this.setState({
isSubmit:true,
gugu:e.target.gugu.value
})
}
render(){
return(
<ul>
<GuguForm
isSubmit={this.state.isSubmit}
onSubmit={this.onSubmit}
gugu={this.state.gugu}
/>
</ul>
)
}
}
ReactDOM.render(
<App/>,
document.querySelector('#root')
)
</script>
</body>
</html>
안녕하세요