```
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);
```



description="Replacing a number with the '-' sign should not clear the value"
      >
        <TestCase.Steps>
          <li>Type "3"</li>
          <li>Select the entire value"</li>
          <li>Type '-' to replace '3' with '-'</li>
        </TestCase.Steps>
        <TestCase.ExpectedResult>
          The field should read "-", not be blank.
        </TestCase.ExpectedResult>
        <NumberTestCase />
      </TestCase>
      <TestCase
          title="Negative numbers"
          description="Typing minus when inserting a negative number should work"
      >
        <TestCase.Steps>
          <li>Type "-"</li>
          <li>Type '3'</li>
        </TestCase.Steps>
        <TestCase.ExpectedResult>
          The field should read "-3".
        </TestCase.ExpectedResult>
        <NumberTestCase />
      </TestCase>
    </FixtureSet>
  );
}
export default NumberInputs;