React Redux - Why mapStateToProps is called before constructor?

Question

Two questions:

1. Why mapStateToProps is called before constructor?

2. As a side-effect of 1

   constructor (props) { base(props

Answer 1

mapStateToProps is not called magically before your constructor. It is done by connect which is a Higher Order Component that executes mapStateToProps before your component is initialised. In fact, connect initialises your component in its body.

connect(mapStateToProps, mapDispatchToProps)(YourComponent)

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Why componentWillReceiveProps not executed? Because React doesn't call componentWillReceiveProps for the initial render, so you should use componentDidMount instead.

componentWillReceiveProps

Invoked when a component is receiving new props. This method is not called for the initial render.