Passing a number to a component

You can either use:

<MyComponent param1={10} param2={20} />

Or:

<MyComponent {...{param1: 10, param2: 20}} />

It seems that in case of integers (and actually for strings as well) I should be passing the numbers via {} like so:

React.render(<Rectangle intValue={10} stringValue={"Hello"} />, document.getElementById('container'));