React

by MuLtDirectX

HTML

<div id="app"></div>

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#app {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  transition: all 0.2s;
}

li {
  margin: 8px 0;
}

h2 {
  font-weight: bold;
  margin-bottom: 15px;
}

.done {
  color: rgba(0, 0, 0, 0.3);
  text-decoration: line-through;
}

input {
  margin-right: 5px;
}

React

class App extends React.Component {

  constructor (props) {
    super(props)
    this.state = {
      number: 0,
    }
  }

  handleChanging(number){
    this.setState(number)
  }

  render () {
    return (
      <div style={{margin:'20px'}}>
        <p>Enter the number: </p>
        <input
          min="0" max="500"
          type='number'
          value={this.state.number}
          onChange={(e) => this.handleChanging({number: e.currentTarget.value})}
        />
        <div style={{height:'4px', background:'red', width:this.state.number+'px', marginTop:'20px'}} />
      </div>
    )
  }
}


ReactDOM.render(<App />, document.querySelector("#app"))