I'm new to ReactJS. I want to be able to set some properties of a React component and then be able to access it from a parent React component. But I'm not entirely sure how to do this. For example, consider the following two classes:

```
export default class SubWindow extends React.Component {

    click(event)
    {
        this.myCollection.push({name:'receiptNum',value:$(event.currentTarget).html()});
    }

    render()
    {
        return (
        <ul>
            <li onClick={this.click.bind(this)}>0</li>
            <li onClick={this.click.bind(this)}>1</li>
            <li onClick={this.click.bind(this)}>2</li>
            <li onClick={this.click.bind(this)}>3</li>
        </ul>
        );

    }

}

export default class MainWindow extends React.Component {

    click(event)
    {
        console.log(SubWindow.myCollection);
    }

    render()
    {
        const SubWindow = require('./SubWindow').default;
        return (
            <SubWindow />
            <button onClick={this.click}>Log subwindow array</button>
        );

    }

}

```

Basically, I want the SubWindow to have a property called `myCollection` which is just an array of JSON objects. `myCollection` gets populated by each click on the list item. 

Later, I want to be able to `console.log(SubWindow.myCollection)` when I press on a button in the parent window. **My question how do I access the `SubWindow.myCollection` from a parent react component?**