```
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);
```



});
  it('should warn with checked and no onChange handler with readOnly specified', () => {
    ReactTestUtils.renderIntoDocument(
      <input type="checkbox" checked="false" readOnly={true} />,
    );
    expectDev(console.error.calls.count()).toBe(0);
    ReactTestUtils.renderIntoDocument(
      <input type="checkbox" checked="false" readOnly={false} />,
    );
    expectDev(console.error.calls.count()).toBe(1);
  });
  it('should update defaultValue to empty string', () => {
    var container = document.createElement('div');
    ReactDOM.render(<input type="text" defaultValue={'foo'} />, container);
    ReactDOM.render(<input type="text" defaultValue={''} />, container);
    expect(container.firstChild.defaultValue).toBe('');
  });
  it('should warn if value is null', () => {
    ReactTestUtils.renderIntoDocument(<input type="text" value={null} />);
    expectDev(console.error.calls.argsFor(0)[0]).toContain(
      '`value` prop on `input` should not be null. ' +
        'Consider using the empty string to clear the component or `undefined` ' +
        'for uncontrolled components.',
    );
    ReactTestUtils.renderIntoDocument(<input type="text" value={null} />);
    expectDev(console.error.calls.count()).toBe(1);
  });
  it('should warn if checked and defaultChecked props are specified', () => {
    ReactTestUtils.renderIntoDocument(
      <input