```
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);
```



}
    }
    var stub = ReactTestUtils.renderIntoDocument(<RadioGroup />);
    var aNode = stub.refs.a;
    var bNode = stub.refs.b;
    var cNode = stub.refs.c;
    expect(aNode.checked).toBe(true);
    expect(bNode.checked).toBe(false);
    
    expect(cNode.checked).toBe(true);
    bNode.checked = true;
    
    
    
    aNode.checked = false;
    expect(cNode.checked).toBe(true);
    
    ReactTestUtils.Simulate.change(bNode);
    
    expect(aNode.checked).toBe(true);
    expect(cNode.checked).toBe(true);
  });
  it('should control radio buttons if the tree updates during render', () => {
    var sharedParent = document.createElement('div');
    var container1 = document.createElement('div');
    var container2 = document.createElement('div');
    sharedParent.appendChild(container1);
    var aNode;
    var bNode;
    class ComponentA extends React.Component {