```
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);
```



<TestCase.ExpectedResult>
          The field should read "3.", preserving the decimal place
        </TestCase.ExpectedResult>
        <NumberTestCase />
        <p className="footnote">
          <b>Notes:</b> Chrome and Safari clear trailing
          decimals on blur. React makes this concession so that the
          value attribute remains in sync with the value property.
        </p>
      </TestCase>
      <TestCase
          title="Decimal precision"
          description="Supports decimal precision greater than 2 places"
      >
        <TestCase.Steps>
          <li>Type "0.01"</li>
        </TestCase.Steps>
        <TestCase.ExpectedResult>
          The field should read "0.01"
        </TestCase.ExpectedResult>
        <NumberTestCase />
      </TestCase>
      <TestCase
          title="Exponent form"
          description="Supports exponent form ('2e4')"
      >
        <TestCase.Steps>
          <li>Type "2e"</li>
          <li>Type 4, to read "2e4"</li>
        </TestCase.Steps>