```
render () {
  <input type="number" value={this.props.value} />
}
```

for example, when the original value is '.98', we need format it to '0.98'. but it is not  take effect。

```javascript
class Test extends React.Component {
 state = {
    value: '.98',
  }
 changeValue = () => {
    alert(0.98);
    this.setState({
      value: '0.98',
    });
  }

 render() {
    return <div>
      <input type="number" value={this.state.value} />
      <button onClick={this.changeValue}>changeValue</button>
    </div>;
  }
}

ReactDOM.render(<Test />, mountNode);
```



<NumberTestCase />
      </TestCase>
      <TestCase
          title="Trailing Zeroes"
          description="Typing '3.0' preserves the trailing zero"
      >
        <TestCase.Steps>
          <li>Type "3.0"</li>
        </TestCase.Steps>
        <TestCase.ExpectedResult>
          The field should read "3.0"
        </TestCase.ExpectedResult>
        <NumberTestCase />
      </TestCase>
      <TestCase
          title="Inserting decimals precision"
          description="Inserting '.' in to '300' maintains the trailing zeroes"
      >
        <TestCase.Steps>
          <li>Type "300"</li>
          <li>Move the cursor to after the "3"</li>
          <li>Type "."</li>
        </TestCase.Steps>
        <TestCase.ExpectedResult>
          The field should read "3.00", not "3"
        </TestCase.ExpectedResult>
        <NumberTestCase />
      </TestCase>
      <TestCase
          title="Replacing numbers with -"