1// ParentComponent.js
2
3// ... other component methods ...
4render() {
5  return <TodoContainer id="1" />
6}
7
8// TodoContainer.js
9
10// <===============>
11// `ownProps` variable contains own component props
12function mapStateToProps(state, ownProps) {
13  return {
14    todo: state.todos[ownProps.id]
15  };
16}
17// <===============>

1function mapStateToProps(state) {  return {    a: 42,    todos: state.todos,    filter: state.visibilityFilter,  }}
2// component will receive: props.a, props.todos, and props.filter